[mlir] [llvm] [clang-tools-extra] [clang] Make clang report garbage target versions. (PR #75373)

[Tobias Hieta via cfe-commits]

tru wrote:

This needs to be cleaned up before it can be merged. There needs to be only one commit in this PR without the merge commits from main.

https://github.com/llvm/llvm-project/pull/75373