[llvm] [VectorCombine][TTI] Disable Load Widening for SPIR-V (PR #227623)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

So what does SPIR-V do in cases where that IR that is created somewhere else? Is there an earlier pass that is canonicalizing it away and Vectorcombine is undoing it? A backend is expected to handle these kinds of thing.

https://github.com/llvm/llvm-project/pull/227623