diff --git a/.travis.yml b/.travis.yml
index d315546930330..827f5fd159ae3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,8 @@
 language: shell
 sudo: required
 dist: trusty
+# FIXME(#44398) shouldn't need to be here
+group: deprecated-2017Q3
 services:
   - docker
 
@@ -125,9 +127,9 @@ matrix:
 env:
   global:
     - SCCACHE_BUCKET=rust-lang-ci-sccache
-    - AWS_ACCESS_KEY_ID=AKIAIMX7VLAS3PZAVLUQ
+    - AWS_ACCESS_KEY_ID=AKIAJAMV3QAMMA6AXHFQ
     # AWS_SECRET_ACCESS_KEY=...
-    - secure: "Pixhh0hXDqGCdOyLtGFjli3J2AtDWIpyb2btIrLe956nCBDRutRoMm6rv5DI9sFZN07Mms7VzNNvhc9wCW1y63JAm414d2Co7Ob8kWMZlz9l9t7ACHuktUiis8yr+S4Quq1Vqd6pqi7pf2J++UxC8R/uLeqVrubzr6+X7AbmEFE="
+    - secure: "j96XxTVOSUf4s4r4htIxn/fvIa5DWbMgLqWl7r8z2QfgUwscmkMXAwXuFNc7s7bGTpV/+CgDiMFFM6BAFLGKutytIF6oA02s9b+usQYnM0th7YQ2AIgm9GtMTJCJp4AoyfFmh8F2faUICBZlfVLUJ34udHEe35vOklix+0k4WDo="
 
 before_install:
   # If we are building a pull request, do the build if $ALLOW_PR == 1
@@ -260,9 +262,9 @@ deploy:
     upload_dir: rustc-builds
     acl: public_read
     region: us-east-1
-    access_key_id: AKIAIPQVNYF2T3DTYIWQ
+    access_key_id: AKIAJVBODR3IA4O72THQ
     secret_access_key:
-      secure: "FBqDqOTeIPMu6v/WYPf4CFSlh9rLRZGKVtpLa5KkyuOhXRTrnEzBduEtS8/FMIxdQImvurhSvxWvqRybMOi4qoVfjMqqpHAI7uBbidbrvAcJoHNsx6BgUNVCIoH6a0UsAjTUtm6/YPIpzbHoLZXPL0GrHPMk6Mu04qVSmcYNWn4="
+      secure: "kUGd3t7JcVWFESgIlzvsM8viZgCA9Encs3creW0xLJaLSeI1iVjlJK4h/2/nO6y224AFrh/GUfsNr4/4AlxPuYb8OU5oC5Lv+Ff2JiRDYtuNpyQSKAQp+bRYytWMtrmhja91h118Mbm90cUfcLPwkdiINgJNTXhPKg5Cqu3VYn0="
     on:
       branch: auto
       condition: $DEPLOY = 1
@@ -274,9 +276,9 @@ deploy:
     upload_dir: rustc-builds-try
     acl: public_read
     region: us-east-1
-    access_key_id: AKIAIPQVNYF2T3DTYIWQ
+    access_key_id: AKIAJVBODR3IA4O72THQ
     secret_access_key:
-      secure: "FBqDqOTeIPMu6v/WYPf4CFSlh9rLRZGKVtpLa5KkyuOhXRTrnEzBduEtS8/FMIxdQImvurhSvxWvqRybMOi4qoVfjMqqpHAI7uBbidbrvAcJoHNsx6BgUNVCIoH6a0UsAjTUtm6/YPIpzbHoLZXPL0GrHPMk6Mu04qVSmcYNWn4="
+      secure: "kUGd3t7JcVWFESgIlzvsM8viZgCA9Encs3creW0xLJaLSeI1iVjlJK4h/2/nO6y224AFrh/GUfsNr4/4AlxPuYb8OU5oC5Lv+Ff2JiRDYtuNpyQSKAQp+bRYytWMtrmhja91h118Mbm90cUfcLPwkdiINgJNTXhPKg5Cqu3VYn0="
     on:
       branch: try
       condition: $DEPLOY = 1 && $ALLOW_TRY = 1
@@ -290,9 +292,9 @@ deploy:
     upload_dir: rustc-builds-alt
     acl: public_read
     region: us-east-1
-    access_key_id: AKIAIPQVNYF2T3DTYIWQ
+    access_key_id: AKIAJVBODR3IA4O72THQ
     secret_access_key:
-      secure: "FBqDqOTeIPMu6v/WYPf4CFSlh9rLRZGKVtpLa5KkyuOhXRTrnEzBduEtS8/FMIxdQImvurhSvxWvqRybMOi4qoVfjMqqpHAI7uBbidbrvAcJoHNsx6BgUNVCIoH6a0UsAjTUtm6/YPIpzbHoLZXPL0GrHPMk6Mu04qVSmcYNWn4="
+      secure: "kUGd3t7JcVWFESgIlzvsM8viZgCA9Encs3creW0xLJaLSeI1iVjlJK4h/2/nO6y224AFrh/GUfsNr4/4AlxPuYb8OU5oC5Lv+Ff2JiRDYtuNpyQSKAQp+bRYytWMtrmhja91h118Mbm90cUfcLPwkdiINgJNTXhPKg5Cqu3VYn0="
     on:
       branch: auto
       condition: $DEPLOY_ALT = 1
diff --git a/appveyor.yml b/appveyor.yml
index f548d6694c80f..62b62ae7c42e9 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,8 +1,8 @@
 environment:
   SCCACHE_BUCKET: rust-lang-ci-sccache
-  AWS_ACCESS_KEY_ID: AKIAIMX7VLAS3PZAVLUQ
+  AWS_ACCESS_KEY_ID: AKIAJAMV3QAMMA6AXHFQ
   AWS_SECRET_ACCESS_KEY:
-    secure: 1UkmbiDd15tWtYbMm5O2Uqm0b0Ur8v1MoSlydxl4ojcroPeerRMlUges0l57py8c
+    secure: 7Y+JiquYedOAgnUU26uL0DPzrxmTtR+qIwG6rNKSuWDffqU3vVZxbGXim9QpTO80
   SCCACHE_DIGEST: f808afabb4a4eb1d7112bcb3fa6be03b61e93412890c88e177c667eb37f46353d7ec294e559b16f9f4b5e894f2185fe7670a0df15fd064889ecbd80f0c34166c
 
   # By default schannel checks revocation of certificates unlike some other SSL
@@ -185,9 +185,9 @@ before_deploy:
 deploy:
   - provider: S3
     skip_cleanup: true
-    access_key_id: AKIAIPQVNYF2T3DTYIWQ
+    access_key_id: AKIAJVBODR3IA4O72THQ
     secret_access_key:
-      secure: +11jsUNFTQ9dq5Ad1i2+PeUJaXluFJ0zIJAXESE1dFT3Kdjku4/eDdgyjgsB6GnV
+      secure: tQWIE+DJHjXaV4np/3YeETkEmXngtIuIgAO/LYKQaUshGLgN8cBCFGG3cHx5lKLt
     bucket: rust-lang-ci
     set_public: true
     region: us-east-1
@@ -202,9 +202,9 @@ deploy:
   # different upload directory and a slightly different trigger
   - provider: S3
     skip_cleanup: true
-    access_key_id: AKIAIPQVNYF2T3DTYIWQ
+    access_key_id: AKIAJVBODR3IA4O72THQ
     secret_access_key:
-      secure: +11jsUNFTQ9dq5Ad1i2+PeUJaXluFJ0zIJAXESE1dFT3Kdjku4/eDdgyjgsB6GnV
+      secure: tQWIE+DJHjXaV4np/3YeETkEmXngtIuIgAO/LYKQaUshGLgN8cBCFGG3cHx5lKLt
     bucket: rust-lang-ci
     set_public: true
     region: us-east-1
diff --git a/src/bootstrap/channel.rs b/src/bootstrap/channel.rs
index d6ce3eb98ecb7..0c22cc2f6c439 100644
--- a/src/bootstrap/channel.rs
+++ b/src/bootstrap/channel.rs
@@ -29,7 +29,7 @@ pub const CFG_RELEASE_NUM: &str = "1.21.0";
 // An optional number to put after the label, e.g. '.2' -> '-beta.2'
 // Be sure to make this starts with a dot to conform to semver pre-release
 // versions (section 9)
-pub const CFG_PRERELEASE_VERSION: &str = ".2";
+pub const CFG_PRERELEASE_VERSION: &str = ".3";
 
 pub struct GitInfo {
     inner: Option<Info>,
diff --git a/src/bootstrap/dist.rs b/src/bootstrap/dist.rs
index bfcfb5f9a37f8..65a59d78d7c5f 100644
--- a/src/bootstrap/dist.rs
+++ b/src/bootstrap/dist.rs
@@ -1081,8 +1081,14 @@ impl Step for Rls {
            .arg("--output-dir").arg(&distdir(build))
            .arg("--non-installed-overlay").arg(&overlay)
            .arg(format!("--package-name={}-{}", name, target))
-           .arg("--component-name=rls")
            .arg("--legacy-manifest-dirs=rustlib,cargo");
+
+        if build.config.channel == "nightly" {
+            cmd.arg("--component-name=rls");
+        } else {
+            cmd.arg("--component-name=rls-preview");
+        }
+
         build.run(&mut cmd);
         distdir(build).join(format!("{}-{}.tar.gz", name, target))
     }
@@ -1279,9 +1285,12 @@ impl Step for Extended {
             cp_r(&work.join(&format!("{}-{}", pkgname(build, "rust-std"), target))
                         .join(format!("rust-std-{}", target)),
                     &exe.join("rust-std"));
-            cp_r(&work.join(&format!("{}-{}", pkgname(build, "rls"), target))
-                        .join("rls"),
-                    &exe.join("rls"));
+            let rls_path = if build.config.channel == "nightly" {
+                work.join(&format!("{}-{}", pkgname(build, "rls"), target)).join("rls")
+            } else {
+                work.join(&format!("{}-{}", pkgname(build, "rls"), target)).join("rls-preview")
+            };
+            cp_r(&rls_path, &exe.join("rls"));
             cp_r(&work.join(&format!("{}-{}", pkgname(build, "rust-analysis"), target))
                         .join(format!("rust-analysis-{}", target)),
                     &exe.join("rust-analysis"));
diff --git a/src/bootstrap/install.rs b/src/bootstrap/install.rs
index 89690e444d1f6..608924c9c28d1 100644
--- a/src/bootstrap/install.rs
+++ b/src/bootstrap/install.rs
@@ -200,7 +200,7 @@ install!((self, builder, _config),
         builder.ensure(dist::Src);
         install_src(builder, self.stage);
     }, ONLY_BUILD;
-    Rustc, "src/librustc", _config.extended, only_hosts: true, {
+    Rustc, "src/librustc", true, only_hosts: true, {
         builder.ensure(dist::Rustc {
             compiler: builder.compiler(self.stage, self.target),
         });
diff --git a/src/libcore/mem.rs b/src/libcore/mem.rs
index 4b866cab1eae2..5dc6a94e1833d 100644
--- a/src/libcore/mem.rs
+++ b/src/libcore/mem.rs
@@ -754,39 +754,39 @@ pub unsafe fn transmute_copy<T, U>(src: &T) -> U {
 /// Opaque type representing the discriminant of an enum.
 ///
 /// See the `discriminant` function in this module for more information.
-#[unstable(feature = "discriminant_value", reason = "recently added, follows RFC", issue = "24263")]
+#[stable(feature = "discriminant_value", since = "1.21.0")]
 pub struct Discriminant<T>(u64, PhantomData<*const T>);
 
 // N.B. These trait implementations cannot be derived because we don't want any bounds on T.
 
-#[unstable(feature = "discriminant_value", reason = "recently added, follows RFC", issue = "24263")]
+#[stable(feature = "discriminant_value", since = "1.21.0")]
 impl<T> Copy for Discriminant<T> {}
 
-#[unstable(feature = "discriminant_value", reason = "recently added, follows RFC", issue = "24263")]
+#[stable(feature = "discriminant_value", since = "1.21.0")]
 impl<T> clone::Clone for Discriminant<T> {
     fn clone(&self) -> Self {
         *self
     }
 }
 
-#[unstable(feature = "discriminant_value", reason = "recently added, follows RFC", issue = "24263")]
+#[stable(feature = "discriminant_value", since = "1.21.0")]
 impl<T> cmp::PartialEq for Discriminant<T> {
     fn eq(&self, rhs: &Self) -> bool {
         self.0 == rhs.0
     }
 }
 
-#[unstable(feature = "discriminant_value", reason = "recently added, follows RFC", issue = "24263")]
+#[stable(feature = "discriminant_value", since = "1.21.0")]
 impl<T> cmp::Eq for Discriminant<T> {}
 
-#[unstable(feature = "discriminant_value", reason = "recently added, follows RFC", issue = "24263")]
+#[stable(feature = "discriminant_value", since = "1.21.0")]
 impl<T> hash::Hash for Discriminant<T> {
     fn hash<H: hash::Hasher>(&self, state: &mut H) {
         self.0.hash(state);
     }
 }
 
-#[unstable(feature = "discriminant_value", reason = "recently added, follows RFC", issue = "24263")]
+#[stable(feature = "discriminant_value", since = "1.21.0")]
 impl<T> fmt::Debug for Discriminant<T> {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         fmt.debug_tuple("Discriminant")
@@ -811,7 +811,6 @@ impl<T> fmt::Debug for Discriminant<T> {
 /// the actual data:
 ///
 /// ```
-/// #![feature(discriminant_value)]
 /// use std::mem;
 ///
 /// enum Foo { A(&'static str), B(i32), C(i32) }
@@ -820,7 +819,7 @@ impl<T> fmt::Debug for Discriminant<T> {
 /// assert!(mem::discriminant(&Foo::B(1))     == mem::discriminant(&Foo::B(2)));
 /// assert!(mem::discriminant(&Foo::B(3))     != mem::discriminant(&Foo::C(3)));
 /// ```
-#[unstable(feature = "discriminant_value", reason = "recently added, follows RFC", issue = "24263")]
+#[stable(feature = "discriminant_value", since = "1.21.0")]
 pub fn discriminant<T>(v: &T) -> Discriminant<T> {
     unsafe {
         Discriminant(intrinsics::discriminant_value(v), PhantomData)
diff --git a/src/librustc/lib.rs b/src/librustc/lib.rs
index 152b2e2aa5ebc..82f01c36fee7f 100644
--- a/src/librustc/lib.rs
+++ b/src/librustc/lib.rs
@@ -24,7 +24,6 @@
 #![feature(conservative_impl_trait)]
 #![feature(const_fn)]
 #![feature(core_intrinsics)]
-#![feature(discriminant_value)]
 #![feature(i128_type)]
 #![cfg_attr(windows, feature(libc))]
 #![feature(never_type)]
@@ -34,7 +33,6 @@
 #![feature(slice_patterns)]
 #![feature(specialization)]
 #![feature(unboxed_closures)]
-#![feature(discriminant_value)]
 #![feature(trace_macros)]
 #![feature(test)]
 
diff --git a/src/librustc_data_structures/lib.rs b/src/librustc_data_structures/lib.rs
index da00ebc4b9ee9..47061883425e2 100644
--- a/src/librustc_data_structures/lib.rs
+++ b/src/librustc_data_structures/lib.rs
@@ -29,7 +29,6 @@
 #![feature(unsize)]
 #![feature(i128_type)]
 #![feature(conservative_impl_trait)]
-#![feature(discriminant_value)]
 #![feature(specialization)]
 
 #![cfg_attr(unix, feature(libc))]
diff --git a/src/librustc_metadata/lib.rs b/src/librustc_metadata/lib.rs
index f79abecf9da4b..f4e6f57c43777 100644
--- a/src/librustc_metadata/lib.rs
+++ b/src/librustc_metadata/lib.rs
@@ -21,7 +21,6 @@
 #![feature(quote)]
 #![feature(rustc_diagnostic_macros)]
 #![feature(specialization)]
-#![feature(discriminant_value)]
 #![feature(rustc_private)]
 
 #[macro_use]
diff --git a/src/librustc_trans/back/link.rs b/src/librustc_trans/back/link.rs
index 4e211d83cff3e..5de48fbce9da9 100644
--- a/src/librustc_trans/back/link.rs
+++ b/src/librustc_trans/back/link.rs
@@ -106,14 +106,32 @@ pub fn build_link_meta(incremental_hashes_map: &IncrementalHashesMap) -> LinkMet
 pub fn get_linker(sess: &Session) -> (String, Command, Vec<(OsString, OsString)>) {
     let envs = vec![("PATH".into(), command_path(sess))];
 
+    // If our linker looks like a batch script on Windows then to execute this
+    // we'll need to spawn `cmd` explicitly. This is primarily done to handle
+    // emscripten where the linker is `emcc.bat` and needs to be spawned as
+    // `cmd /c emcc.bat ...`.
+    //
+    // This worked historically but is needed manually since #42436 (regression
+    // was tagged as #42791) and some more info can be found on #44443 for
+    // emscripten itself.
+    let cmd = |linker: &str| {
+        if cfg!(windows) && linker.ends_with(".bat") {
+            let mut cmd = Command::new("cmd");
+            cmd.arg("/c").arg(linker);
+            cmd
+        } else {
+            Command::new(linker)
+        }
+    };
+
     if let Some(ref linker) = sess.opts.cg.linker {
-        (linker.clone(), Command::new(linker), envs)
+        (linker.clone(), cmd(linker), envs)
     } else if sess.target.target.options.is_like_msvc {
         let (cmd, envs) = msvc_link_exe_cmd(sess);
         ("link.exe".to_string(), cmd, envs)
     } else {
         let linker = &sess.target.target.options.linker;
-        (linker.clone(), Command::new(&linker), envs)
+        (linker.clone(), cmd(linker), envs)
     }
 }
 
diff --git a/src/test/run-pass/discriminant_value-wrapper.rs b/src/test/run-pass/discriminant_value-wrapper.rs
index 2dbda0be18d98..d7a32423710fd 100644
--- a/src/test/run-pass/discriminant_value-wrapper.rs
+++ b/src/test/run-pass/discriminant_value-wrapper.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(discriminant_value)]
-
 use std::mem;
 
 enum ADT {