Remove some old filters from the x86 disassembler table builder.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192275 91177308-0d34-0410-b5e6-96231b3b80d8
Add missing HasAVX512 predicate.

This was only working because AVX had cheaper rules in all cases.
I'm sure there are other places in this file where predicates are missing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192276 91177308-0d34-0410-b5e6-96231b3b80d8