[llvm] [InstCombine] Add ctpop(A | B) + ctpop(A & B) -> ctpop(A) + ctpop(B) (PR #79089)

[via llvm-commits]

AtariDreams wrote:

> @AtariDreams Does this pattern exist in some real-world applications?

Given the popcount(A|B) does exist, it makes sense that popcount(A&B) + popcount(A|B) exists.

https://github.com/llvm/llvm-project/pull/79089