build rustc with 1CGU on x86_64-pc-windows-msvc

Author: lqd

.github/workflows/ci.yml

@@ -438,7 +438,7 @@ jobs:
             os: windows-2019-8core-32gb
           - name: dist-x86_64-msvc
             env:
-              RUST_CONFIGURE_ARGS: "--build=x86_64-pc-windows-msvc --host=x86_64-pc-windows-msvc --target=x86_64-pc-windows-msvc --enable-full-tools --enable-profiler"
+              RUST_CONFIGURE_ARGS: "--build=x86_64-pc-windows-msvc --host=x86_64-pc-windows-msvc --target=x86_64-pc-windows-msvc --enable-full-tools --enable-profiler --set rust.codegen-units=1"
               SCRIPT: python x.py build --set rust.debug=true opt-dist && PGO_HOST=x86_64-pc-windows-msvc ./build/x86_64-pc-windows-msvc/stage0-tools-bin/opt-dist windows-ci -- python x.py dist bootstrap --include-default-paths
               DIST_REQUIRE_ALL_TOOLS: 1
             os: windows-2019-8core-32gb

src/ci/github-actions/ci.yml

@@ -687,6 +687,7 @@ jobs:
                 --target=x86_64-pc-windows-msvc
                 --enable-full-tools
                 --enable-profiler
+                --set rust.codegen-units=1
               SCRIPT: python x.py build --set rust.debug=true opt-dist && PGO_HOST=x86_64-pc-windows-msvc ./build/x86_64-pc-windows-msvc/stage0-tools-bin/opt-dist windows-ci -- python x.py dist bootstrap --include-default-paths
               DIST_REQUIRE_ALL_TOOLS: 1
             <<: *job-windows-8c