[clang] [Driver] Restore compiler-rt arch suffix for PS and Windows (PR #89775)

[Paul T Robinson via cfe-commits]

pogo59 wrote:

> LLVM_ENABLE_PER_TARGET_RUNTIME_DIR=on 

I'm unable to find what code this affects. I don't see it mentioned anywhere in clang/lib or clang/include.

It does seem like it should control the behavior of `ToolChain::getCompilerRT`; where I had added the Windows/PS check, seems like it should check the config variable instead. It's obvious that OS-based checks are not appropriate, as @tru reports using the new scheme but MSVC clearly uses the old scheme, both on Windows.

How do CMake variables turn into something that controls code behavior?

https://github.com/llvm/llvm-project/pull/89775