[SKX] Enabling mask logic instructions: encoding, lowering
Instructions: KAND{BWDQ}, KANDN{BWDQ}, KOR{BWDQ}, KXOR{BWDQ}, KXNOR{BWDQ}

Reviewed by Elena Demikhovsky <elena.demikhovsky@intel.com>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214081 91177308-0d34-0410-b5e6-96231b3b80d8