[llvm] [AArch64][GlobalISel] Legalize G_LOAD for v4s8 Vector (PR #82989)

[David Green via llvm-commits]

https://github.com/davemgreen approved this pull request.

LGTM, along with the G_STORE version.

The tests show there might be some opportunity to use larger loads for some of the odd-sized-vectors if we know they are aligned, but that is a separate issue from this.

https://github.com/llvm/llvm-project/pull/82989