[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>

llvm-svn: 214081