[llvm] [SelectionDAG] Legalize vector types for atomic load (PR #111414)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> This patch will only cover 1 x vectors. The patch is fine as-is, but the message should change to reflect this. An additional step is required to handle any other vector size

Still only handles 1 x vectors 

https://github.com/llvm/llvm-project/pull/111414