[llvm] [LowerBufferFatPointers] Don't lose data from unaligned < word vectors (PR #132981)

[Krzysztof Drewniak via llvm-commits]

krzysz00 wrote:

Closing because this unfairly pessimizes loads that aren't trying to go out of bounds - will be implementing `llvm.intr.masked.load` for ptr addrspace(7) instead

https://github.com/llvm/llvm-project/pull/132981