[compiler-rt] [llvm] [compiler-rt][X86] Use functions in cpuid.h instead of inline assembly (PR #97877)

[Fangrui Song via llvm-commits]

MaskRay wrote:

clang/lib/Headers/cpuid.h did not define `__get_cpuid_count` before f6e8408a116405d0cc25b506e8c5b60ab4ab7bcd (2017). Clang 5.0.0 (Sep 2017) contains the commit. Nice:)

https://github.com/llvm/llvm-project/pull/97877