[clang] Patch series to reapply #118734 and substantially improve it (PR #120534)

[via cfe-commits]

dyung wrote:

> > @dyung - I believe this PR may be a credible path to address the issues hit with your MSVC builders, would appreciate any help testing it in advance if possible.
> 
> Sure, I'll give it a try

You seem to still be working on it, can you tell me which commit I should try building/testing when you are done?

https://github.com/llvm/llvm-project/pull/120534