[llvm] [InstCombine] Avoid Allocating Arrays Too Large For the Target (PR #70980)

[Qiongsi Wu via llvm-commits]

qiongsiwu wrote:

Thanks for the comment @nikic and @arsenm !! The PR is updated to address Matt's comments. As mentioned https://github.com/llvm/llvm-project/pull/70980#issuecomment-1792654827 and https://github.com/llvm/llvm-project/pull/70980#issuecomment-1792657916, it is not clear what the correct behivour is without further discussion, so this PR now leaves the `alloca`s alone if the implied array type is too big to minimize the changes to current behaviours. 


https://github.com/llvm/llvm-project/pull/70980