[llvm] [InstCombine] Fold align assume into load's !align metadata if possible. (PR #108958)

[Yingwei Zheng via llvm-commits]

dtcxzyw wrote:

> (other alternative would be to just keep the assumptions, but I was hoping this patch would help to avoid introducing too many new instructions when doing something like #108961)

Agree. Removing assumptions reduces compilation time :)
>   llvm/Interp.cpp.ll 36858214354 33892745069 -8.05%
  llvm/Disasm.cpp.ll 3399768227 3263050730 -4.02%
  llvm/APINotesReader.cpp.ll 7143171077 7021418904 -1.70%
  llvm/COFFObjectFile.cpp.ll 3399105265 3356267000 -1.26%
  darktable/histogram.c.ll 1007474874 995703620 -1.17%

https://github.com/llvm/llvm-project/pull/108958