Revert "enable ThinLTO for rustc on x86_64-pc-windows-msvc dist builds"

This lead to a miscompilation in at least `char::is_whitespace` and
probably in more unknown places.....

This reverts commit 684663e.

Author: Noratrieb

.github/workflows/ci.yml

@@ -438,7 +438,7 @@ jobs:
             os: windows-latest-xl
           - 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 --set rust.lto=thin"
+              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"
               SCRIPT: PGO_HOST=x86_64-pc-windows-msvc src/ci/pgo.sh python x.py dist bootstrap --include-default-paths
               DIST_REQUIRE_ALL_TOOLS: 1
             os: windows-latest-xl

src/ci/github-actions/ci.yml

@@ -675,7 +675,6 @@ jobs:
                 --target=x86_64-pc-windows-msvc
                 --enable-full-tools
                 --enable-profiler
-                --set rust.lto=thin
               SCRIPT: PGO_HOST=x86_64-pc-windows-msvc src/ci/pgo.sh python x.py dist bootstrap --include-default-paths
               DIST_REQUIRE_ALL_TOOLS: 1
             <<: *job-windows-xl