Auto merge of #112267 - lqd:win-1cgu, r=Kobzol

Build `rustc` with 1CGU on `x86_64-pc-windows-msvc`

Distribute `x86_64-pc-windows-msvc` artifacts built with `rust.codegen-units=1`, like we already do on Linux.

1) effect on code size on `x86_64-pc-windows-msvc`: it's a 3.67% reduction on `rustc_driver.dll`
- before, [`41d97c8a5dea2731b0e56fe97cd7cb79e21cff79`](https://ci-artifacts.rust-lang.org/rustc-builds/41d97c8a5dea2731b0e56fe97cd7cb79e21cff79/rustc-nightly-x86_64-pc-windows-msvc.tar.xz): 137605632
- after, [`704aaa875e4acccc973cbe4579e66afbac425691`](https://ci-artifacts.rust-lang.org/rustc-builds/704aaa875e4acccc973cbe4579e66afbac425691/rustc-nightly-x86_64-pc-windows-msvc.tar.xz): 132551680

2) time it took on CI
- the [first `try` build](https://github.com/rust-lang-ci/rust/actions/runs/8155647651/job/22291592507) took: 1h 31m
- the [second `try` build](https://github.com/rust-lang-ci/rust/actions/runs/8157043594/job/22295790552) took: 1h 32m

3) most recent perf results:
- on a slightly noisy desktop [here](rust-lang/rust#112267 (comment))
- ChrisDenton's results [here](rust-lang/rust#112267 (comment))

Related tracking issue for build configuration: #103595