[llvm] [NFC] Eliminate need of Emacs tag and file name in file header (PR #118553)

[Rahul Joshi via llvm-commits]

jurahul wrote:

Thanks. @AaronBallman will wait a couple of days to give you a chance to look as well. Will merge towards EOW.

https://github.com/llvm/llvm-project/pull/118553