[llvm] [InstCombine] Extend folding of aggregate construction to cases when source aggregates are partially available (PR #100828)

[Yingwei Zheng via llvm-commits]

dtcxzyw wrote:

IR diff looks good to me. I believe the regression can be addressed by using `simplifyInstruction` in `FoldOpIntoSelect`: https://alive2.llvm.org/ce/z/HiwgPk. We discussed about this in https://github.com/llvm/llvm-project/pull/84686#issuecomment-1987344128.


https://github.com/llvm/llvm-project/pull/100828