[X86] Fix some places where macro arguments to intrinsics weren't cast to...

[X86] Fix some places where macro arguments to intrinsics weren't cast to _m512(i|d)/_m256(i|d/_m128(i|d) first.

The majority of the cases were correct. This fixes the few that weren't.

I also removed some superfluous parentheses in non-macros that confused by attempts at grepping for missing casts.

llvm-svn: 333615