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

[Paul T Robinson via cfe-commits]

pogo59 wrote:

I've redone the decision to be based on the setting of LLVM_ENABLE_PER_TARGET_RUNTIME_DIR and updated the tests to work with either setting as much as possible. Tests that explicitly look for the per-target _directory_ are enabled only if the CMake variable is ON.

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