[clang] [clang][CodeGen] Emit `llvm.tbaa.errno` metadata during module creation (PR #125258)

[Antonio Frighetto via cfe-commits]

antoniofrighetto wrote:

A kind ping for @rjmccall. As previously were requested changes, any other concern with this? (Only the Clang-side change has been left here.)

https://github.com/llvm/llvm-project/pull/125258