PR25157 identifies a bug where a load plus a vector shuffle is
incorrectly converted into an LXVDSX instruction. That optimization
is only valid if the load is of a doubleword, and in the noted case,
it was not. This corrects that problem.
Joint patch with Eric Schweitz, who provided the bugpoint-reduced test
case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250324 91177308-0d34-0410-b5e6-96231b3b80d8
