[AVX512] Don't use 32-bit elements version of AND/OR/XOR/ANDN during isel...

[AVX512] Don't use 32-bit elements version of AND/OR/XOR/ANDN during isel unless we're matching a masked op or broadcast

Selecting 32-bit element logical ops without a select or broadcast requires matching a bitconvert on the inputs to the and. But that's a weird thing to rely on. It's entirely possible that one of the inputs doesn't have a bitcast and one does.

Since there's no functional difference, just remove the extra patterns and save some isel table size.

Differential Revision: https://reviews.llvm.org/D36854

llvm-svn: 312138