[llvm] [SimplifyCFG] Add foldCondStoreToSelect optimization (PR #207654)

[Karthika Devi C via llvm-commits]

kartcq wrote:

> 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/207654#issuecomment-4889583427) for details.

Thanks for reporting this @dtcxzyw. I will look into this.

https://github.com/llvm/llvm-project/pull/207654