[llvm] [GlobalISel] Refactor extractParts() (PR #75223)

[Amara Emerson via llvm-commits]

aemerson wrote:

> > Moved extractParts() and extractVectorParts() from LegalizerHelper to Utils to be able to use it in different passes.
> 
> Could you elaborate on which passes may want to use this functionality while not using the `LegalizerHelper` directly?

These are intended to be used in a combiner here: https://github.com/llvm/llvm-project/pull/75832

https://github.com/llvm/llvm-project/pull/75223