[llvm] [InstCombine] Set !prof metadata on Selects identified by add.ll test (PR #158743)

[Alan Zhao via llvm-commits]

alanzhao1 wrote:

> I'd still like to see a (InstCombine-specific) helper that allows directly replacing `SelectInst::Create` with a single call.

Done

https://github.com/llvm/llvm-project/pull/158743