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

[Chandler Carruth via cfe-commits]

chandlerc wrote:

> > > I'll try it and let you know. Give me about an hour or so.
> > 
> > Awesome! But no huge rush, mostly just hoping this happens to dodge whatever has been tripping up things here.
> 
> Sorry for the delay, but the failures still seem to be present. :( (The tests are still running, but the amount of output being generated is slowing things down).

Strange... Is it the *same* output??

Can you upload the output somewhere? 

> 
> Just a heads up, we are probably going to be upgrading our internal machines and upstream bot to a later build of VS2019 to avoid this issue. I'm validating a newer build today and if all goes well, I am going to try and get it deployed on Friday.

While this generally seems good, I'd like to avoid requiring even more MSVC upgrades, so interested in knowing how this is failing.



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