Support APX CFCMOV

Support APX CFCMOV

The CMOVcc instruction proposed by EVEX has four different forms,
corresponding to the four possible combinations of EVEX.ND and EVEX.NF
values.

In the encoder part, when the CFCMOV template supports EVEX_NF, it means that
it requires EVEX.NF to be 1.

In the decoder part, CFCMOV_Fixup is used to reverse source and destination
operands in the 2-operand case.

gas/ChangeLog:

        * config/tc-i386.c (build_apx_evex_prefix): Set NF bit for cfcmov
        when the insn template supports EVEX_NF.
        * testsuite/gas/i386/x86-64-apx-inval.l: Add invalid tests for cfcmov.
        * testsuite/gas/i386/x86-64-apx-inval.s: Ditto.
        * testsuite/gas/i386/x86-64.exp: Add tests for cfcmov and cmov.
        * testsuite/gas/i386/x86-64-apx-cfcmov-intel.d: Ditto.
        * testsuite/gas/i386/x86-64-apx-cfcmov.d: Ditto.
        * testsuite/gas/i386/x86-64-apx-cfcmov.s: Ditto.

opcodes/ChangeLog:

        * i386-dis-evex-prefix.h: Add cfcmov instructions.
        * i386-dis.c (CFCMOV_Fixup): Special handling of cfcmov.
        (putop): Print 'cf' for cfcmov instructions.
        * i386-opc.h (EVEX_NF): New.
        * i386-opc.tbl: Add cfcmov instructions.
        * i386-mnem.h: Regerated.
        * i386-tbl.h: Regerated.