[llvm] IR/Verifier: Allow vector type in atomic load and store (PR #120384)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> My initial assumption was that `load atomic <2 x i32>` is, in terms of semantics, equivalent to `load atomic i64` with appropriate bitcasts 

That is what this should be 



https://github.com/llvm/llvm-project/pull/120384