Add support for vectors to this utility function. As noted in the diffs, this utility is used in several transforms so adding the generic logic gets picked up in several places.
The LangRef wording is rather vague here, but you can see analogous logic in VNCoercion.cpp and the Verifier's rules for inttoptr/ptrtoint.
Note that the isNoopCast function is currently incorrect for vectors. I plan on fixing that in a follow up, and then trying to merge the code paths. (Before this change, isBitOrNoopPointerCastable was merely incomplete, not incorrect.)
I think this is fixed vector specific, so you likely want FixedVectorType.