[LegalizeVectorTypes] When unrolling in WidenVecRes_Convert, make sure we use...

[LegalizeVectorTypes] When unrolling in WidenVecRes_Convert, make sure we use the original vector element count. Not min of the widened result type and the possibly widened input type.

If the input type is widened as well, but we still were forced to unroll, we shouldn't be considering the widened input element count. We should only create as many scalar operations as the original type called for.

This will be important for an upcoming patch.

llvm-svn: 344403