[llvm] [PAC][InstCombine] Replace auth+sign with resign (PR #130807)

[Daniil Kovalev via llvm-commits]

https://github.com/kovdan01 approved this pull request.

LGTM, thanks! It would be very nice if someone with a better InstCombine background than me can take a look at this before merging.

https://github.com/llvm/llvm-project/pull/130807