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

[Fangrui Song via cfe-commits]

MaskRay wrote:

Note that if the code uses LLVM_ENABLE_PER_TARGET_RUNTIME_DIR to decide whether to probe the new or old hierarchy first, these clang/test/Driver `libclang_rt.asan.a`/`libclang_rt.asan-x86_64.a` tests will need a `REQUIRES: a_feature_signaling_the_config`, otherwise the tests would fail on the other configuration. Alternatively, create dummy files for these clang/test/Driver tests, but this would be huge amount of work.

I do wish that Windows users migrate to LLVM_ENABLE_PER_TARGET_RUNTIME_DIR=on to match `llvm/runtimes/CMakeLists.txt`.

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