Update x86 CPU_XXX_FLAGS handling

Update x86 CPU_XXX_FLAGS handling

Support defining CPU_XXX_FLAGS with other CPU_XXX_FLAGS.  Update
CPU_XXX_FLAGS to enable more bits like x87 and SYSCALL.  Don't enable
MMX when enabling SSE, AVX or AVX512.  Don't disable AVX nor AVX512 when
disabling SSE.  Don't disable AVX512 when disabling AVX.  Disable F16C,
FMA, FMA4 and XOP when disabling AVX.  Add 87, no287, no387, no687,
nosse2, nosse3, nossse3, nosse4.1, nosse4.2, nosse4 and noavx2 directives
to x86 assembler.

TODO: Add more .noXXX, like .noavx512f, directives to x86 assembler.

gas/

	PR gas/20145
	* config/tc-i386.c (cpu_arch): Add 687.
	(cpu_noarch): Add no287, no387, no687, nosse2, nosse3, nossse3,
	nosse4.1, nosse4.2, nosse4 and noavx2.
	(parse_real_register): Check cpuregmmx instead of cpummx for MMX
	register.  Check cpuregxmm instead of cpusse for XMM register.
	Check cpuregymm instead of cpuavx for YMM register.  Check
	cpuregzmm/cpuregmask instead of cpuavx512f for ZMMM/mask register.
	* doc/c-i386.texi: Mention 687, no287, no387, no687, nosse2,
	nosse3, nossse3, nosse4.1, nosse4.2, nosse4 and noavx2.
	* testsuite/gas/i386/arch-10-prefetchw.d (as): Add mmx.
	* testsuite/gas/i386/arch-10.d (as): Likewise.
	* testsuite/gas/i386/arch-11.s: Add ".arch .mmx".
	* testsuite/gas/i386/i386.exp: Pass mmx to assembler for
	arch-10-3 and arch-10-4.  Run no87-3, nosse-4, nosse-5, noavx-3
	and noavx-4.
	* testsuite/gas/i386/no87-3.l: New file.
	* testsuite/gas/i386/no87-3.s: Likewise.
	* testsuite/gas/i386/noavx-3.l: Likewise.
	* testsuite/gas/i386/noavx-3.s: Likewise.
	* testsuite/gas/i386/noavx-4.d: Likewise.
	* testsuite/gas/i386/noavx-4.s: Likewise.
	* testsuite/gas/i386/nosse-4.l: Likewise.
	* testsuite/gas/i386/nosse-4.s: Likewise.
	* testsuite/gas/i386/nosse-5.d: Likewise.
	* testsuite/gas/i386/nosse-5.s: Likewise.

opcodes/

	PR gas/20145
	* i386-gen.c (cpu_flag_init): Update CPU_XXX_FLAGS.  Remove
	CpuMMX from CPU_SSE_FLAGS.  Remove AVX and AVX512 bits from
	CPU_ANY_SSE_FLAGS.  Remove AVX512 bits from CPU_ANY_AVX_FLAGS.
	Add CPU_XSAVE_FLAGS to CPU_XSAVEOPT_FLAGS, CPU_XSAVE_FLAGS and
	CpuXSAVEC.  Add CPU_AVX_FLAGS to CpuF16C.  Remove CpuMMX from
	CPU_AVX512F_FLAGS, CPU_AVX512CD_FLAGS, CPU_AVX512ER_FLAGS,
	CPU_AVX512PF_FLAGS, CPU_AVX512DQ_FLAGS and CPU_AVX512BW_FLAGS.
	Add CPU_SSE2_FLAGS to CPU_SHA_FLAGS.   Add CPU_ANY_287_FLAGS,
	CPU_ANY_387_FLAGS, CPU_ANY_687_FLAGS, CPU_ANY_SSE2_FLAGS,
	CPU_ANY_SSE3_FLAGS, CPU_ANY_SSSE3_FLAGS, CPU_ANY_SSE4_1_FLAGS,
	CPU_ANY_SSE4_2_FLAGS and CPU_ANY_AVX2_FLAGS.  Enable CpuRegMMX
	for MMX.  Enable CpuRegXMM for SSE, AVX and AVX512.  Enable
	CpuRegYMM for AVX and AVX512VL,  Enable CpuRegZMM and
	CpuRegMask for AVX512.
	(cpu_flags): Add CpuRegMMX, CpuRegXMM, CpuRegYMM, CpuRegZMM
	and CpuRegMask.
	(set_bitfield_from_cpu_flag_init): New function.
	(set_bitfield): Remove const on f.  Call
	set_bitfield_from_cpu_flag_init to handle CPU_XXX_FLAGS.
	* i386-opc.h (CpuRegMMX): New.
	(CpuRegXMM): Likewise.
	(CpuRegYMM): Likewise.
	(CpuRegZMM): Likewise.
	(CpuRegMask): Likewise.
	(i386_cpu_flags): Add cpuregmmx, cpuregxmm, cpuregymm, cpuregzmm
	and cpuregmask.
	* i386-init.h: Regenerated.
	* i386-tbl.h: Likewise.