Bug 1533010 - Update Windows Rust to 1.34 beta r=glandium

This is needed for cross-language LTO (bug 1512723). We don't want to block on waiting for 1.34's release, so we'll get a head start now, but we'll update to the final 1.34 release when available. Rust Forge estimates the release at 11 April.

Differential Revision: https://phabricator.services.mozilla.com/D25851

--HG--
extra : moz-landing-system : lando

taskcluster/ci/toolchain/cbindgen.yml

@@ -52,4 +52,4 @@ win64-cbindgen:
         arguments: ['x86_64-pc-windows-msvc']
         toolchain-artifact: public/build/cbindgen.tar.bz2
     toolchains:
-        - win64-rust-1.32
+        - win64-rust-1.34

taskcluster/ci/toolchain/grcov.yml

@@ -38,4 +38,4 @@ win64-grcov:
     run:
         toolchain-artifact: public/build/grcov.tar.bz2
     toolchains:
-        - win64-rust-1.32
+        - win64-rust-1.34

taskcluster/ci/toolchain/rust.yml

@@ -125,12 +125,12 @@ win64-rust-1.28:
         ]
         toolchain-artifact: public/build/rustc.tar.bz2
 
-win64-rust-1.32:
+win64-rust-1.34:
     treeherder:
         symbol: TW64(rust)
     run:
         arguments: [
-            '--channel', '1.32.0',
+            '--channel', 'beta-2019-03-27',
             '--host', 'x86_64-pc-windows-msvc',
             '--target', 'x86_64-pc-windows-msvc',
             '--target', 'i686-pc-windows-msvc',
@@ -157,7 +157,7 @@ win64-aarch64-rust:
         symbol: TW64(rust-aarch64)
     run:
         arguments: [
-            '--channel', '1.32.0',
+            '--channel', 'beta-2019-03-27',
             '--host', 'x86_64-pc-windows-msvc',
             '--target', 'x86_64-pc-windows-msvc',
             '--target', 'aarch64-pc-windows-msvc',

toolkit/library/rust/shared/build.rs

@@ -5,7 +5,7 @@ use rustc_version::{version, Version};
 fn main() {
     let ver = version().unwrap();
     let mut bootstrap = false;
-    let max_oom_hook_version = Version::parse("1.33.0-alpha").unwrap();
+    let max_oom_hook_version = Version::parse("1.35.0-alpha").unwrap();
 
     if ver >= Version::parse("1.28.0-alpha").unwrap() && ver < max_oom_hook_version {
         println!("cargo:rustc-cfg=feature=\"oom_with_hook\"");