[llvm] [LV] Add VPWiden{Load|Store}EVLRecipe into emitInvalidCostRemarks(). (PR #119708)

[David Sherwood via llvm-commits]

david-arm wrote:

> > > Tests?
> > 
> > 
> > It hard to find a test case that using VPWidenLoadEVL and the cost is invalid. Something I can imagine is that gather/scatter under `--triple riscv64 -mattr=+v` will return invalid cost. However, this pattern will not be vectorized in the upstream compiler.
> 
> If the assumption is we cannot encounter those, could it be an assert instead? Not sure if the type switch would already assert.

That would work I guess. It doesn't look like TypeSwitch would assert by itself though. My assumption was that an assert should only be added if there is something explicit in the code that should prevent that from happening. 

https://github.com/llvm/llvm-project/pull/119708