[llvm] [LV] Convert gather loads with invariant stride into strided loads (PR #147297)

[Mel Chen via llvm-commits]

Mel-Chen wrote:

@lukel97 @wangpc-pp
Elvis https://github.com/llvm/llvm-project/pull/149955
Elvis is working on improving the gather/scatter cost model. This should help enable strided accesses.

https://github.com/llvm/llvm-project/pull/147297