[llvm] [LoopInterchange] Forbid interchange if load store type wider than element type (PR #77885)

[via llvm-commits]

ShivaChen wrote:

Thanks for your kind explanation and bring more cases that could have overwritten.
Another angle could be would the casting between int and char types is well-defined behavior.
If it isn't, should we abandon the PR because the compiler may not be able to guarantee the results?

https://github.com/llvm/llvm-project/pull/77885