Auto merge of #55171 - kennytm:rollup, r=kennytm

Rollup of 18 pull requests

Successful merges:

 - #54646 (improve documentation on std::thread::sleep)
 - #54933 (Cleanup the rest of codegen_llvm)
 - #54964 (Run both lldb and gdb tests)
 - #55016 (Deduplicate some code and compile-time values around vtables)
 - #55031 (Improve verify_llvm_ir config option)
 - #55050 (doc std::fmt: the Python inspiration is already mentioned in precedin…)
 - #55077 (rustdoc: Use dyn keyword when rendering dynamic traits)
 - #55080 (Detect if access to localStorage is forbidden by the user's browser)
 - #55090 (regression test for move out of borrow via pattern)
 - #55102 (resolve: Do not skip extern prelude during speculative resolution)
 - #55104 (Add test for #34229)
 - #55111 ([Rustc Book] Explain --cfg's arguments)
 - #55122 (Cleanup mir/borrowck)
 - #55127 (Remove HybridBitSet::dummy)
 - #55128 (Fix LLVMRustInlineAsmVerify return type mismatch)
 - #55142 (miri: layout should not affect CTFE checks (outside of validation))
 - #55151 (Cleanup nll)
 - #55161 ([librustdoc] Disable spellcheck for search field)

Author: bors

src/bootstrap/bin/rustc.rs

@@ -287,10 +287,6 @@ fn main() {
         cmd.arg("--cfg").arg("parallel_queries");
     }
 
-    if env::var_os("RUSTC_VERIFY_LLVM_IR").is_some() {
-        cmd.arg("-Z").arg("verify-llvm-ir");
-    }
-
     if env::var_os("RUSTC_DENY_WARNINGS").is_some() && env::var_os("RUSTC_EXTERNAL_TOOL").is_none()
     {
         cmd.arg("-Dwarnings");

src/bootstrap/builder.rs

@@ -1000,10 +1000,6 @@ impl<'a> Builder<'a> {
             cargo.env("RUSTC_BACKTRACE_ON_ICE", "1");
         }
 
-        if self.config.rust_verify_llvm_ir {
-            cargo.env("RUSTC_VERIFY_LLVM_IR", "1");
-        }
-
         cargo.env("RUSTC_VERBOSE", self.verbosity.to_string());
 
         // in std, we want to avoid denying warnings for stage 0 as that makes cfg's painful.