[compiler-rt] [compiler-rt] Fix '-Wmacro-redefined' errors (PR #100337)

[Mitch Phillips via llvm-commits]

hctim wrote:

I think for now it's best to update the original patch and check it, then re-land it all at once. I've reverted the original + the 1st fix-forward already in 59e1c6cd63eb9287df6516f9a5ae564075e9c218 and e7a3aeb1f86b8d45815b834e4e20b1fc7e71705d respectively.

https://github.com/llvm/llvm-project/pull/100337