[clang] Workaround for MSVC ARM64 build performance regression (PR #65215)

[Tobias Hieta via cfe-commits]

tru wrote:

I suspect maybe the MSVC_VERSION check might exclude clang-cl, but we should make sure, because @omjavaid is correct, we shouldn't apply this to clang-cl unless it shows the same problems.

https://github.com/llvm/llvm-project/pull/65215