diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2ead68638fa4a..ffaa2b03df9e7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -43,7 +43,7 @@ jobs:
           - name: mingw-check
             os: ubuntu-latest-xl
             env: {}
-          - name: x86_64-gnu-llvm-9
+          - name: x86_64-gnu-llvm-10
             os: ubuntu-latest-xl
             env: {}
           - name: x86_64-gnu-tools
@@ -265,7 +265,7 @@ jobs:
           - name: x86_64-gnu-distcheck
             os: ubuntu-latest-xl
             env: {}
-          - name: x86_64-gnu-llvm-9
+          - name: x86_64-gnu-llvm-10
             env:
               RUST_BACKTRACE: 1
             os: ubuntu-latest-xl
diff --git a/RELEASES.md b/RELEASES.md
index 579a811048387..e0894c83f1b03 100644
--- a/RELEASES.md
+++ b/RELEASES.md
@@ -51,6 +51,8 @@ Libraries
 - [`io::Empty` now implements `io::Seek`.][78044]
 - [`rc::Weak<T>` and `sync::Weak<T>`'s methods such as `as_ptr` are now implemented for
   `T: ?Sized` types.][80764]
+- [`Div` and `Rem` by their `NonZero` variant is now implemented for all unsigned integers.][79134]
+
 
 Stabilized APIs
 ---------------
@@ -73,6 +75,8 @@ Stabilized APIs
 - [`str::split_inclusive`]
 - [`sync::OnceState`]
 - [`task::Wake`]
+- [`VecDeque::range`]
+- [`VecDeque::range_mut`]
 
 Cargo
 -----
@@ -116,6 +120,7 @@ Compatibility Notes
     - `thumbv7neon-unknown-linux-gnueabihf`
     - `armv7-unknown-linux-gnueabi`
     - `x86_64-unknown-linux-gnux32`
+- [`atomic::spin_loop_hint` has been deprecated.][80966] It's recommended to use `hint::spin_loop` instead.
 
 Internal Only
 -------------
@@ -147,6 +152,8 @@ Internal Only
 [80749]: https://github.com/rust-lang/rust/pull/80749
 [80662]: https://github.com/rust-lang/rust/pull/80662
 [77885]: https://github.com/rust-lang/rust/pull/77885
+[79134]: https://github.com/rust-lang/rust/pull/79134
+[80966]: https://github.com/rust-lang/rust/pull/80966
 [cargo/8997]: https://github.com/rust-lang/cargo/pull/8997
 [cargo/9112]: https://github.com/rust-lang/cargo/pull/9112
 [feature-resolver@2.0]: https://doc.rust-lang.org/nightly/cargo/reference/features.html#feature-resolver-version-2
@@ -168,6 +175,8 @@ Internal Only
 [`Seek::stream_position`]: https://doc.rust-lang.org/nightly/std/io/trait.Seek.html#method.stream_position
 [`Peekable::next_if`]: https://doc.rust-lang.org/nightly/std/iter/struct.Peekable.html#method.next_if
 [`Peekable::next_if_eq`]: https://doc.rust-lang.org/nightly/std/iter/struct.Peekable.html#method.next_if_eq
+[`VecDeque::range`]: https://doc.rust-lang.org/nightly/std/collections/struct.VecDeque.html#method.range
+[`VecDeque::range_mut`]: https://doc.rust-lang.org/nightly/std/collections/struct.VecDeque.html#method.range_mut
 
 Version 1.50.0 (2021-02-11)
 ============================
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index 5385c4d72e4ba..046e7fc70fced 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -520,10 +520,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                         }
                         self.visit_fn_ret_ty(&f.decl.output)
                     }
-                    TyKind::ImplTrait(def_node_id, _) => {
-                        self.lctx.allocate_hir_id_counter(def_node_id);
-                        visit::walk_ty(self, t);
-                    }
                     _ => visit::walk_ty(self, t),
                 }
             }
@@ -1431,14 +1427,10 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                         // Add a definition for the in-band `Param`.
                         let def_id = self.resolver.local_def_id(def_node_id);
 
-                        self.allocate_hir_id_counter(def_node_id);
-
-                        let hir_bounds = self.with_hir_id_owner(def_node_id, |this| {
-                            this.lower_param_bounds(
-                                bounds,
-                                ImplTraitContext::Universal(in_band_ty_params, parent_def_id),
-                            )
-                        });
+                        let hir_bounds = self.lower_param_bounds(
+                            bounds,
+                            ImplTraitContext::Universal(in_band_ty_params, parent_def_id),
+                        );
                         // Set the name to `impl Bound1 + Bound2`.
                         let ident = Ident::from_str_and_span(&pprust::ty_to_string(t), span);
                         in_band_ty_params.push(hir::GenericParam {
diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs
index 21473f3b1143c..c580456805ad1 100644
--- a/compiler/rustc_codegen_llvm/src/context.rs
+++ b/compiler/rustc_codegen_llvm/src/context.rs
@@ -101,10 +101,6 @@ fn to_llvm_tls_model(tls_model: TlsModel) -> llvm::ThreadLocalMode {
     }
 }
 
-fn strip_x86_address_spaces(data_layout: String) -> String {
-    data_layout.replace("-p270:32:32-p271:32:32-p272:64:64-", "-")
-}
-
 fn strip_powerpc64_vectors(data_layout: String) -> String {
     data_layout.replace("-v256:256:256-v512:512:512", "")
 }
@@ -119,11 +115,6 @@ pub unsafe fn create_module(
     let llmod = llvm::LLVMModuleCreateWithNameInContext(mod_name.as_ptr(), llcx);
 
     let mut target_data_layout = sess.target.data_layout.clone();
-    if llvm_util::get_version() < (10, 0, 0)
-        && (sess.target.arch == "x86" || sess.target.arch == "x86_64")
-    {
-        target_data_layout = strip_x86_address_spaces(target_data_layout);
-    }
     if llvm_util::get_version() < (12, 0, 0) && sess.target.arch == "powerpc64" {
         target_data_layout = strip_powerpc64_vectors(target_data_layout);
     }
diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs
index 9b6f67166bdaa..66499fbb8da92 100644
--- a/compiler/rustc_errors/src/emitter.rs
+++ b/compiler/rustc_errors/src/emitter.rs
@@ -434,9 +434,15 @@ pub trait Emitter {
         span: &mut MultiSpan,
         children: &mut Vec<SubDiagnostic>,
     ) {
+        let source_map = if let Some(ref sm) = source_map {
+            sm
+        } else {
+            return;
+        };
         debug!("fix_multispans_in_extern_macros: before: span={:?} children={:?}", span, children);
-        for span in iter::once(&mut *span).chain(children.iter_mut().map(|child| &mut child.span)) {
-            self.fix_multispan_in_extern_macros(source_map, span);
+        self.fix_multispan_in_extern_macros(source_map, span);
+        for child in children.iter_mut() {
+            self.fix_multispan_in_extern_macros(source_map, &mut child.span);
         }
         debug!("fix_multispans_in_extern_macros: after: span={:?} children={:?}", span, children);
     }
@@ -444,16 +450,7 @@ pub trait Emitter {
     // This "fixes" MultiSpans that contain `Span`s pointing to locations inside of external macros.
     // Since these locations are often difficult to read,
     // we move these spans from the external macros to their corresponding use site.
-    fn fix_multispan_in_extern_macros(
-        &self,
-        source_map: &Option<Lrc<SourceMap>>,
-        span: &mut MultiSpan,
-    ) {
-        let sm = match source_map {
-            Some(ref sm) => sm,
-            None => return,
-        };
-
+    fn fix_multispan_in_extern_macros(&self, source_map: &Lrc<SourceMap>, span: &mut MultiSpan) {
         // First, find all the spans in external macros and point instead at their use site.
         let replacements: Vec<(Span, Span)> = span
             .primary_spans()
@@ -461,7 +458,7 @@ pub trait Emitter {
             .copied()
             .chain(span.span_labels().iter().map(|sp_label| sp_label.span))
             .filter_map(|sp| {
-                if !sp.is_dummy() && sm.is_imported(sp) {
+                if !sp.is_dummy() && source_map.is_imported(sp) {
                     let maybe_callsite = sp.source_callsite();
                     if sp != maybe_callsite {
                         return Some((sp, maybe_callsite));
@@ -1232,7 +1229,6 @@ impl EmitterWriter {
         is_secondary: bool,
     ) -> io::Result<()> {
         let mut buffer = StyledBuffer::new();
-        let header_style = if is_secondary { Style::HeaderMsg } else { Style::MainHeaderMsg };
 
         if !msp.has_primary_spans() && !msp.has_span_labels() && is_secondary && !self.short_message
         {
@@ -1257,6 +1253,7 @@ impl EmitterWriter {
                 buffer.append(0, &code, Style::Level(*level));
                 buffer.append(0, "]", Style::Level(*level));
             }
+            let header_style = if is_secondary { Style::HeaderMsg } else { Style::MainHeaderMsg };
             if *level != Level::FailureNote {
                 buffer.append(0, ": ", header_style);
             }
@@ -1470,9 +1467,7 @@ impl EmitterWriter {
                     let mut to_add = FxHashMap::default();
 
                     for (depth, style) in depths {
-                        if multilines.get(&depth).is_some() {
-                            multilines.remove(&depth);
-                        } else {
+                        if multilines.remove(&depth).is_none() {
                             to_add.insert(depth, style);
                         }
                     }
@@ -1726,14 +1721,13 @@ impl EmitterWriter {
                     if !self.short_message {
                         draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1);
                     }
-                    match emit_to_destination(
+                    if let Err(e) = emit_to_destination(
                         &buffer.render(),
                         level,
                         &mut self.dst,
                         self.short_message,
                     ) {
-                        Ok(()) => (),
-                        Err(e) => panic!("failed to emit error: {}", e),
+                        panic!("failed to emit error: {}", e)
                     }
                 }
                 if !self.short_message {
diff --git a/compiler/rustc_llvm/build.rs b/compiler/rustc_llvm/build.rs
index 621363bed80e1..301ed639f3b51 100644
--- a/compiler/rustc_llvm/build.rs
+++ b/compiler/rustc_llvm/build.rs
@@ -88,16 +88,6 @@ fn main() {
         "riscv",
     ];
 
-    let mut version_cmd = Command::new(&llvm_config);
-    version_cmd.arg("--version");
-    let version_output = output(&mut version_cmd);
-    let mut parts = version_output.split('.').take(2).filter_map(|s| s.parse::<u32>().ok());
-    let (major, _minor) = if let (Some(major), Some(minor)) = (parts.next(), parts.next()) {
-        (major, minor)
-    } else {
-        (8, 0)
-    };
-
     let required_components = &[
         "ipo",
         "bitreader",
@@ -123,10 +113,6 @@ fn main() {
         println!("cargo:rustc-cfg=llvm_component=\"{}\"", component);
     }
 
-    if major >= 9 {
-        println!("cargo:rustc-cfg=llvm_has_msp430_asm_parser");
-    }
-
     // Link in our own LLVM shims, compiled with the same flags as LLVM
     let mut cmd = Command::new(&llvm_config);
     cmd.arg("--cxxflags");
diff --git a/compiler/rustc_llvm/llvm-wrapper/ArchiveWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/ArchiveWrapper.cpp
index 2797fe8df4a8e..97541e615da83 100644
--- a/compiler/rustc_llvm/llvm-wrapper/ArchiveWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/ArchiveWrapper.cpp
@@ -91,11 +91,7 @@ extern "C" void LLVMRustDestroyArchive(LLVMRustArchiveRef RustArchive) {
 extern "C" LLVMRustArchiveIteratorRef
 LLVMRustArchiveIteratorNew(LLVMRustArchiveRef RustArchive) {
   Archive *Archive = RustArchive->getBinary();
-#if LLVM_VERSION_GE(10, 0)
   std::unique_ptr<Error> Err = std::make_unique<Error>(Error::success());
-#else
-  std::unique_ptr<Error> Err = llvm::make_unique<Error>(Error::success());
-#endif
   auto Cur = Archive->child_begin(*Err);
   if (*Err) {
     LLVMRustSetLastError(toString(std::move(*Err)).c_str());
diff --git a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
index 22ceb57762b92..b8d5b50dcb565 100644
--- a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
@@ -65,13 +65,9 @@ extern "C" void LLVMInitializePasses() {
 }
 
 extern "C" void LLVMTimeTraceProfilerInitialize() {
-#if LLVM_VERSION_GE(10, 0)
   timeTraceProfilerInitialize(
       /* TimeTraceGranularity */ 0,
       /* ProcName */ "rustc");
-#else
-  timeTraceProfilerInitialize();
-#endif
 }
 
 extern "C" void LLVMTimeTraceProfilerFinish(const char* FileName) {
@@ -596,7 +592,6 @@ enum class LLVMRustFileType {
   ObjectFile,
 };
 
-#if LLVM_VERSION_GE(10, 0)
 static CodeGenFileType fromRust(LLVMRustFileType Type) {
   switch (Type) {
   case LLVMRustFileType::AssemblyFile:
@@ -607,18 +602,6 @@ static CodeGenFileType fromRust(LLVMRustFileType Type) {
     report_fatal_error("Bad FileType.");
   }
 }
-#else
-static TargetMachine::CodeGenFileType fromRust(LLVMRustFileType Type) {
-  switch (Type) {
-  case LLVMRustFileType::AssemblyFile:
-    return TargetMachine::CGFT_AssemblyFile;
-  case LLVMRustFileType::ObjectFile:
-    return TargetMachine::CGFT_ObjectFile;
-  default:
-    report_fatal_error("Bad FileType.");
-  }
-}
-#endif
 
 extern "C" LLVMRustResult
 LLVMRustWriteOutputFile(LLVMTargetMachineRef Target, LLVMPassManagerRef PMR,
@@ -868,13 +851,11 @@ LLVMRustOptimizeWithNewPassManager(
         }
       );
 #else
-#if LLVM_VERSION_GE(10, 0)
       PipelineStartEPCallbacks.push_back(
         [Options](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
           MPM.addPass(MemorySanitizerPass(Options));
         }
       );
-#endif
       OptimizerLastEPCallbacks.push_back(
         [Options](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
           FPM.addPass(MemorySanitizerPass(Options));
@@ -892,13 +873,11 @@ LLVMRustOptimizeWithNewPassManager(
         }
       );
 #else
-#if LLVM_VERSION_GE(10, 0)
       PipelineStartEPCallbacks.push_back(
         [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
           MPM.addPass(ThreadSanitizerPass());
         }
       );
-#endif
       OptimizerLastEPCallbacks.push_back(
         [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
           FPM.addPass(ThreadSanitizerPass());
@@ -989,13 +968,11 @@ LLVMRustOptimizeWithNewPassManager(
 
       MPM.addPass(AlwaysInlinerPass(EmitLifetimeMarkers));
 
-# if LLVM_VERSION_GE(10, 0)
       if (PGOOpt) {
         PB.addPGOInstrPassesForO0(
             MPM, DebugPassManager, PGOOpt->Action == PGOOptions::IRInstr,
             /*IsCS=*/false, PGOOpt->ProfileFile, PGOOpt->ProfileRemappingFile);
       }
-# endif
 #endif
     } else {
 #if LLVM_VERSION_GE(12, 0)
@@ -1366,11 +1343,7 @@ LLVMRustCreateThinLTOData(LLVMRustThinLTOModule *modules,
                           int num_modules,
                           const char **preserved_symbols,
                           int num_symbols) {
-#if LLVM_VERSION_GE(10, 0)
   auto Ret = std::make_unique<LLVMRustThinLTOData>();
-#else
-  auto Ret = llvm::make_unique<LLVMRustThinLTOData>();
-#endif
 
   // Load each module's summary and merge it into one combined index
   for (int i = 0; i < num_modules; i++) {
@@ -1463,7 +1436,6 @@ LLVMRustCreateThinLTOData(LLVMRustThinLTOModule *modules,
         ExportedGUIDs.insert(GUID);
     }
   }
-#if LLVM_VERSION_GE(10, 0)
   auto isExported = [&](StringRef ModuleIdentifier, ValueInfo VI) {
     const auto &ExportList = Ret->ExportLists.find(ModuleIdentifier);
     return (ExportList != Ret->ExportLists.end() &&
@@ -1471,15 +1443,6 @@ LLVMRustCreateThinLTOData(LLVMRustThinLTOModule *modules,
       ExportedGUIDs.count(VI.getGUID());
   };
   thinLTOInternalizeAndPromoteInIndex(Ret->Index, isExported, isPrevailing);
-#else
-  auto isExported = [&](StringRef ModuleIdentifier, GlobalValue::GUID GUID) {
-    const auto &ExportList = Ret->ExportLists.find(ModuleIdentifier);
-    return (ExportList != Ret->ExportLists.end() &&
-      ExportList->second.count(GUID)) ||
-      ExportedGUIDs.count(GUID);
-  };
-  thinLTOInternalizeAndPromoteInIndex(Ret->Index, isExported);
-#endif
 
   return Ret.release();
 }
@@ -1636,11 +1599,7 @@ struct LLVMRustThinLTOBuffer {
 
 extern "C" LLVMRustThinLTOBuffer*
 LLVMRustThinLTOBufferCreate(LLVMModuleRef M) {
-#if LLVM_VERSION_GE(10, 0)
   auto Ret = std::make_unique<LLVMRustThinLTOBuffer>();
-#else
-  auto Ret = llvm::make_unique<LLVMRustThinLTOBuffer>();
-#endif
   {
     raw_string_ostream OS(Ret->data);
     {
diff --git a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
index 0391feaf499f3..2bb22fd4447fb 100644
--- a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
@@ -541,11 +541,6 @@ static DINode::DIFlags fromRust(LLVMRustDIFlags Flags) {
   if (isSet(Flags & LLVMRustDIFlags::FlagAppleBlock)) {
     Result |= DINode::DIFlags::FlagAppleBlock;
   }
-#if LLVM_VERSION_LT(10, 0)
-  if (isSet(Flags & LLVMRustDIFlags::FlagBlockByrefStruct)) {
-    Result |= DINode::DIFlags::FlagBlockByrefStruct;
-  }
-#endif
   if (isSet(Flags & LLVMRustDIFlags::FlagVirtual)) {
     Result |= DINode::DIFlags::FlagVirtual;
   }
@@ -910,9 +905,7 @@ extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateStaticVariable(
       unwrapDI<DIDescriptor>(Context), StringRef(Name, NameLen),
       StringRef(LinkageName, LinkageNameLen),
       unwrapDI<DIFile>(File), LineNo, unwrapDI<DIType>(Ty), IsLocalToUnit,
-#if LLVM_VERSION_GE(10, 0)
       /* isDefined */ true,
-#endif
       InitExpr, unwrapDIPtr<MDNode>(Decl),
       /* templateParams */ nullptr,
       AlignInBits);
@@ -1099,19 +1092,11 @@ inline section_iterator *unwrap(LLVMSectionIteratorRef SI) {
 
 extern "C" size_t LLVMRustGetSectionName(LLVMSectionIteratorRef SI,
                                          const char **Ptr) {
-#if LLVM_VERSION_GE(10, 0)
   auto NameOrErr = (*unwrap(SI))->getName();
   if (!NameOrErr)
     report_fatal_error(NameOrErr.takeError());
   *Ptr = NameOrErr->data();
   return NameOrErr->size();
-#else
-  StringRef Ret;
-  if (std::error_code EC = (*unwrap(SI))->getName(Ret))
-    report_fatal_error(EC.message());
-  *Ptr = Ret.data();
-  return Ret.size();
-#endif
 }
 
 // LLVMArrayType function does not support 64-bit ElementCount
@@ -1450,47 +1435,28 @@ extern "C" LLVMValueRef LLVMRustBuildMemCpy(LLVMBuilderRef B,
                                             LLVMValueRef Dst, unsigned DstAlign,
                                             LLVMValueRef Src, unsigned SrcAlign,
                                             LLVMValueRef Size, bool IsVolatile) {
-#if LLVM_VERSION_GE(10, 0)
   return wrap(unwrap(B)->CreateMemCpy(
       unwrap(Dst), MaybeAlign(DstAlign),
       unwrap(Src), MaybeAlign(SrcAlign),
       unwrap(Size), IsVolatile));
-#else
-  return wrap(unwrap(B)->CreateMemCpy(
-      unwrap(Dst), DstAlign,
-      unwrap(Src), SrcAlign,
-      unwrap(Size), IsVolatile));
-#endif
 }
 
 extern "C" LLVMValueRef LLVMRustBuildMemMove(LLVMBuilderRef B,
                                              LLVMValueRef Dst, unsigned DstAlign,
                                              LLVMValueRef Src, unsigned SrcAlign,
                                              LLVMValueRef Size, bool IsVolatile) {
-#if LLVM_VERSION_GE(10, 0)
   return wrap(unwrap(B)->CreateMemMove(
       unwrap(Dst), MaybeAlign(DstAlign),
       unwrap(Src), MaybeAlign(SrcAlign),
       unwrap(Size), IsVolatile));
-#else
-  return wrap(unwrap(B)->CreateMemMove(
-      unwrap(Dst), DstAlign,
-      unwrap(Src), SrcAlign,
-      unwrap(Size), IsVolatile));
-#endif
 }
 
 extern "C" LLVMValueRef LLVMRustBuildMemSet(LLVMBuilderRef B,
                                             LLVMValueRef Dst, unsigned DstAlign,
                                             LLVMValueRef Val,
                                             LLVMValueRef Size, bool IsVolatile) {
-#if LLVM_VERSION_GE(10, 0)
   return wrap(unwrap(B)->CreateMemSet(
       unwrap(Dst), unwrap(Val), unwrap(Size), MaybeAlign(DstAlign), IsVolatile));
-#else
-  return wrap(unwrap(B)->CreateMemSet(
-      unwrap(Dst), unwrap(Val), unwrap(Size), DstAlign, IsVolatile));
-#endif
 }
 
 extern "C" LLVMValueRef
@@ -1676,11 +1642,7 @@ struct LLVMRustModuleBuffer {
 
 extern "C" LLVMRustModuleBuffer*
 LLVMRustModuleBufferCreate(LLVMModuleRef M) {
-#if LLVM_VERSION_GE(10, 0)
   auto Ret = std::make_unique<LLVMRustModuleBuffer>();
-#else
-  auto Ret = llvm::make_unique<LLVMRustModuleBuffer>();
-#endif
   {
     raw_string_ostream OS(Ret->data);
     {
diff --git a/compiler/rustc_llvm/src/lib.rs b/compiler/rustc_llvm/src/lib.rs
index 592010d78cf87..555aefb192948 100644
--- a/compiler/rustc_llvm/src/lib.rs
+++ b/compiler/rustc_llvm/src/lib.rs
@@ -125,10 +125,7 @@ pub fn initialize_available_targets() {
         LLVMInitializeMSP430TargetInfo,
         LLVMInitializeMSP430Target,
         LLVMInitializeMSP430TargetMC,
-        LLVMInitializeMSP430AsmPrinter
-    );
-    init_target!(
-        all(llvm_component = "msp430", llvm_has_msp430_asm_parser),
+        LLVMInitializeMSP430AsmPrinter,
         LLVMInitializeMSP430AsmParser
     );
     init_target!(
diff --git a/compiler/rustc_middle/src/hir/map/collector.rs b/compiler/rustc_middle/src/hir/map/collector.rs
index 4602ed695fe68..501e7d624d2e4 100644
--- a/compiler/rustc_middle/src/hir/map/collector.rs
+++ b/compiler/rustc_middle/src/hir/map/collector.rs
@@ -373,26 +373,8 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
     }
 
     fn visit_generic_param(&mut self, param: &'hir GenericParam<'hir>) {
-        if let hir::GenericParamKind::Type {
-            synthetic: Some(hir::SyntheticTyParamKind::ImplTrait),
-            ..
-        } = param.kind
-        {
-            debug_assert_eq!(
-                param.hir_id.owner,
-                self.definitions.opt_hir_id_to_local_def_id(param.hir_id).unwrap()
-            );
-            self.with_dep_node_owner(param.hir_id.owner, param, |this, hash| {
-                this.insert_with_hash(param.span, param.hir_id, Node::GenericParam(param), hash);
-
-                this.with_parent(param.hir_id, |this| {
-                    intravisit::walk_generic_param(this, param);
-                });
-            });
-        } else {
-            self.insert(param.span, param.hir_id, Node::GenericParam(param));
-            intravisit::walk_generic_param(self, param);
-        }
+        self.insert(param.span, param.hir_id, Node::GenericParam(param));
+        intravisit::walk_generic_param(self, param);
     }
 
     fn visit_const_param_default(&mut self, param: HirId, ct: &'hir AnonConst) {
diff --git a/compiler/rustc_passes/src/hir_id_validator.rs b/compiler/rustc_passes/src/hir_id_validator.rs
index 79e3b5952acaf..944a3097a61c3 100644
--- a/compiler/rustc_passes/src/hir_id_validator.rs
+++ b/compiler/rustc_passes/src/hir_id_validator.rs
@@ -172,17 +172,4 @@ impl<'a, 'hir> intravisit::Visitor<'hir> for HirIdValidator<'a, 'hir> {
         // we are currently in. So for those it's correct that they have a
         // different owner.
     }
-
-    fn visit_generic_param(&mut self, param: &'hir hir::GenericParam<'hir>) {
-        if let hir::GenericParamKind::Type {
-            synthetic: Some(hir::SyntheticTyParamKind::ImplTrait),
-            ..
-        } = param.kind
-        {
-            // Synthetic impl trait parameters are owned by the node of the desugared type.
-            // This means it is correct for them to have a different owner.
-        } else {
-            intravisit::walk_generic_param(self, param);
-        }
-    }
 }
diff --git a/compiler/rustc_save_analysis/src/dump_visitor.rs b/compiler/rustc_save_analysis/src/dump_visitor.rs
index 15435df32bec1..65f16ff45a10c 100644
--- a/compiler/rustc_save_analysis/src/dump_visitor.rs
+++ b/compiler/rustc_save_analysis/src/dump_visitor.rs
@@ -320,15 +320,6 @@ impl<'tcx> DumpVisitor<'tcx> {
         for param in generics.params {
             match param.kind {
                 hir::GenericParamKind::Lifetime { .. } => {}
-                hir::GenericParamKind::Type {
-                    synthetic: Some(hir::SyntheticTyParamKind::ImplTrait),
-                    ..
-                } => {
-                    return self
-                        .nest_typeck_results(self.tcx.hir().local_def_id(param.hir_id), |this| {
-                            this.visit_generics(generics)
-                        });
-                }
                 hir::GenericParamKind::Type { .. } => {
                     let param_ss = param.name.ident().span;
                     let name = escape(self.span.snippet(param_ss));
diff --git a/library/core/src/cell.rs b/library/core/src/cell.rs
index 770169219aad2..9a2908c275da8 100644
--- a/library/core/src/cell.rs
+++ b/library/core/src/cell.rs
@@ -188,7 +188,7 @@
 //! [`Rc<T>`]: ../../std/rc/struct.Rc.html
 //! [`RwLock<T>`]: ../../std/sync/struct.RwLock.html
 //! [`Mutex<T>`]: ../../std/sync/struct.Mutex.html
-//! [`atomic`]: ../../core/sync/atomic/index.html
+//! [`atomic`]: crate::sync::atomic
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
diff --git a/library/core/src/num/dec2flt/algorithm.rs b/library/core/src/num/dec2flt/algorithm.rs
index a5fbdc6ee2d48..313b6870ac9d3 100644
--- a/library/core/src/num/dec2flt/algorithm.rs
+++ b/library/core/src/num/dec2flt/algorithm.rs
@@ -62,10 +62,9 @@ mod fpu_precision {
         // any `u16`
         unsafe {
             asm!(
-                "fldcw ({})",
+                "fldcw word ptr [{}]",
                 in(reg) &cw,
-                // FIXME: We are using ATT syntax to support LLVM 8 and LLVM 9.
-                options(att_syntax, nostack),
+                options(nostack),
             )
         }
     }
@@ -87,10 +86,9 @@ mod fpu_precision {
         // any `u16`
         unsafe {
             asm!(
-                "fnstcw ({})",
+                "fnstcw word ptr [{}]",
                 in(reg) &mut cw,
-                // FIXME: We are using ATT syntax to support LLVM 8 and LLVM 9.
-                options(att_syntax, nostack),
+                options(nostack),
             )
         }
 
diff --git a/library/profiler_builtins/build.rs b/library/profiler_builtins/build.rs
index 2de6db762b2fb..1b1f11798d74d 100644
--- a/library/profiler_builtins/build.rs
+++ b/library/profiler_builtins/build.rs
@@ -24,13 +24,11 @@ fn main() {
         "InstrProfilingPlatformLinux.c",
         "InstrProfilingPlatformOther.c",
         "InstrProfilingPlatformWindows.c",
+        "InstrProfilingRuntime.cpp",
         "InstrProfilingUtil.c",
         "InstrProfilingValue.c",
         "InstrProfilingVersionVar.c",
         "InstrProfilingWriter.c",
-        // This file was renamed in LLVM 10.
-        "InstrProfilingRuntime.cc",
-        "InstrProfilingRuntime.cpp",
         // These files were added in LLVM 11.
         "InstrProfilingInternal.c",
         "InstrProfilingBiasVar.c",
diff --git a/library/std/src/sys/sgx/abi/mem.rs b/library/std/src/sys/sgx/abi/mem.rs
index 3753fdd353617..1e743894a9fea 100644
--- a/library/std/src/sys/sgx/abi/mem.rs
+++ b/library/std/src/sys/sgx/abi/mem.rs
@@ -36,10 +36,9 @@ pub fn image_base() -> u64 {
     let base: u64;
     unsafe {
         asm!(
-            "lea IMAGE_BASE(%rip), {}",
+            "lea {}, qword ptr [rip + IMAGE_BASE]",
             lateout(reg) base,
-            // NOTE(#76738): ATT syntax is used to support LLVM 8 and 9.
-            options(att_syntax, nostack, preserves_flags, nomem, pure),
+            options(nostack, preserves_flags, nomem, pure),
         )
     };
     base
diff --git a/library/std/src/sys/sgx/ext/arch.rs b/library/std/src/sys/sgx/ext/arch.rs
index 7488e7e5dc9ec..730db34e73328 100644
--- a/library/std/src/sys/sgx/ext/arch.rs
+++ b/library/std/src/sys/sgx/ext/arch.rs
@@ -36,8 +36,7 @@ pub fn egetkey(request: &Align512<[u8; 512]>) -> Result<Align16<[u8; 16]>, u32>
             inlateout("eax") ENCLU_EGETKEY => error,
             in("rbx") request,
             in("rcx") out.as_mut_ptr(),
-            // NOTE(#76738): ATT syntax is used to support LLVM 8 and 9.
-            options(att_syntax, nostack),
+            options(nostack),
         );
 
         match error {
@@ -66,8 +65,7 @@ pub fn ereport(
             in("rbx") targetinfo,
             in("rcx") reportdata,
             in("rdx") report.as_mut_ptr(),
-            // NOTE(#76738): ATT syntax is used to support LLVM 8 and 9.
-            options(att_syntax, preserves_flags, nostack),
+            options(preserves_flags, nostack),
         );
 
         report.assume_init()
diff --git a/src/bootstrap/native.rs b/src/bootstrap/native.rs
index fb5127bac54df..305ff071dbba3 100644
--- a/src/bootstrap/native.rs
+++ b/src/bootstrap/native.rs
@@ -347,11 +347,11 @@ fn check_llvm_version(builder: &Builder<'_>, llvm_config: &Path) {
     let version = output(cmd.arg("--version"));
     let mut parts = version.split('.').take(2).filter_map(|s| s.parse::<u32>().ok());
     if let (Some(major), Some(_minor)) = (parts.next(), parts.next()) {
-        if major >= 9 {
+        if major >= 10 {
             return;
         }
     }
-    panic!("\n\nbad LLVM version: {}, need >=9.0\n\n", version)
+    panic!("\n\nbad LLVM version: {}, need >=10.0\n\n", version)
 }
 
 fn configure_cmake(
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-llvm-9/Dockerfile b/src/ci/docker/host-x86_64/x86_64-gnu-llvm-10/Dockerfile
similarity index 95%
rename from src/ci/docker/host-x86_64/x86_64-gnu-llvm-9/Dockerfile
rename to src/ci/docker/host-x86_64/x86_64-gnu-llvm-10/Dockerfile
index 38eac6588b02c..0d32a9ec5eb84 100644
--- a/src/ci/docker/host-x86_64/x86_64-gnu-llvm-9/Dockerfile
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-llvm-10/Dockerfile
@@ -13,8 +13,8 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   cmake \
   sudo \
   gdb \
-  llvm-9-tools \
-  llvm-9-dev \
+  llvm-10-tools \
+  llvm-10-dev \
   libedit-dev \
   libssl-dev \
   pkg-config \
@@ -28,7 +28,7 @@ RUN sh /scripts/sccache.sh
 # using llvm-link-shared due to libffi issues -- see #34486
 ENV RUST_CONFIGURE_ARGS \
       --build=x86_64-unknown-linux-gnu \
-      --llvm-root=/usr/lib/llvm-9 \
+      --llvm-root=/usr/lib/llvm-10 \
       --enable-llvm-link-shared \
       --set rust.thin-lto-import-instr-limit=10
 
diff --git a/src/ci/github-actions/ci.yml b/src/ci/github-actions/ci.yml
index c0a84444a5928..a59a90b86bcaf 100644
--- a/src/ci/github-actions/ci.yml
+++ b/src/ci/github-actions/ci.yml
@@ -280,7 +280,7 @@ jobs:
           - name: mingw-check
             <<: *job-linux-xl
 
-          - name: x86_64-gnu-llvm-9
+          - name: x86_64-gnu-llvm-10
             <<: *job-linux-xl
 
           - name: x86_64-gnu-tools
@@ -412,7 +412,7 @@ jobs:
           - name: x86_64-gnu-distcheck
             <<: *job-linux-xl
 
-          - name: x86_64-gnu-llvm-9
+          - name: x86_64-gnu-llvm-10
             env:
               RUST_BACKTRACE: 1
             <<: *job-linux-xl
diff --git a/src/test/codegen/simd-intrinsic/simd-intrinsic-transmute-array.rs b/src/test/codegen/simd-intrinsic/simd-intrinsic-transmute-array.rs
index 56466a78d5a69..ae13d91ddeba4 100644
--- a/src/test/codegen/simd-intrinsic/simd-intrinsic-transmute-array.rs
+++ b/src/test/codegen/simd-intrinsic/simd-intrinsic-transmute-array.rs
@@ -1,6 +1,5 @@
 // ignore-tidy-linelength
 // compile-flags: -C no-prepopulate-passes
-// min-llvm-version 8.0
 
 #![crate_type = "lib"]
 
diff --git a/src/test/rustdoc-gui/README.md b/src/test/rustdoc-gui/README.md
new file mode 100644
index 0000000000000..499a98a3d2237
--- /dev/null
+++ b/src/test/rustdoc-gui/README.md
@@ -0,0 +1,12 @@
+The tests present here are used to test the generated HTML from rustdoc. The
+goal is to prevent unsound/unexpected GUI changes.
+
+This is using the [browser-ui-test] framework to do so. It works as follows:
+
+It wraps [puppeteer] to send commands to a web browser in order to navigate and
+test what's being currently displayed in the web page.
+
+You can find more information and its documentation in its [repository][browser-ui-test].
+
+[browser-ui-test]: https://github.com/GuillaumeGomez/browser-UI-test/
+[puppeteer]: https://pptr.dev/
diff --git a/src/test/ui/simd/simd-intrinsic-generic-reduction.rs b/src/test/ui/simd/simd-intrinsic-generic-reduction.rs
index 8b5afeac0bc2d..7193fb3527fa2 100644
--- a/src/test/ui/simd/simd-intrinsic-generic-reduction.rs
+++ b/src/test/ui/simd/simd-intrinsic-generic-reduction.rs
@@ -2,7 +2,6 @@
 #![allow(non_camel_case_types)]
 
 // ignore-emscripten
-// min-system-llvm-version: 9.0
 
 // Test that the simd_reduce_{op} intrinsics produce the correct results.