[llvm] [InstCombine] Narrow the ctpop when upper bits are known zero (PR #196537)

[Yingwei Zheng via llvm-commits]

https://github.com/dtcxzyw requested changes to this pull request.

A correctness issue was identified by [llvm-hackme](https://github.com/dtcxzyw/llvm-hackme). Please see the [issue comment](https://github.com/llvm/llvm-project/pull/196537#issuecomment-4407125315) for details.

https://github.com/llvm/llvm-project/pull/196537