[Hexagon] Don't use garbage mask in HvxSelector::shuffp2

The function shuffp2 was breaking up a wide shuffle into a pair of
narrower ones, except that the narrower shuffle masks were actually
uninitialized.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324243 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed