Enable Intel AVX512_BITALG instructions.

Enable Intel AVX512_BITALG instructions.

Intel has disclosed a set of new instructions. The spec is
https://software.intel.com/sites/default/files/managed/c5/15/architecture-instruction-set-extensions-programming-reference.pdf

gas/

	* config/tc-i386.c (cpu_arch): Add .avx512_bitalg.
	(cpu_noarch): noavx512_bitalg.
	* doc/c-i386.texi: Document .avx512_bitalg, noavx512_bitalg.
	* testsuite/gas/i386/i386.exp: Add AVX512_BITALG tests.
	* testsuite/gas/i386/avx512f_bitalg-intel.d: New test.
	* testsuite/gas/i386/avx512f_bitalg.d: Likewise.
	* testsuite/gas/i386/avx512f_bitalg.s: Likewise.
	* testsuite/gas/i386/avx512vl_bitalg-intel.d: Likewise.
	* testsuite/gas/i386/avx512vl_bitalg.d: Likewise.
	* testsuite/gas/i386/avx512vl_bitalg.s: Likewise.
	* testsuite/gas/i386/x86-64-avx512f_bitalg-intel.d: Likewise.
	* testsuite/gas/i386/x86-64-avx512f_bitalg.d: Likewise.
	* testsuite/gas/i386/x86-64-avx512f_bitalg.s: Likewise.
	* testsuite/gas/i386/x86-64-avx512vl_bitalg-intel.d: Likewise.
	* testsuite/gas/i386/x86-64-avx512vl_bitalg.d: Likewise.
	* testsuite/gas/i386/x86-64-avx512vl_bitalg.s: Likewise.

opcodes/

	* i386-dis.c (enum): Add PREFIX_EVEX_0F3854, PREFIX_EVEX_0F388F.
	(enum): Add EVEX_W_0F3854_P_2.
	* i386-dis-evex.h (evex_table): Updated.
	* i386-gen.c (cpu_flag_init): Add CPU_AVX512_BITALG,
	CPU_ANY_AVX512_BITALG_FLAGS. Update CPU_ANY_AVX512F_FLAGS.
	(cpu_flags): Add CpuAVX512_BITALG.
	* i386-opc.h (enum): Add CpuAVX512_BITALG.
	(i386_cpu_flags): Add cpuavx512_bitalg..
	* i386-opc.tbl: Add Intel AVX512_BITALG instructions.
	* i386-init.h: Regenerate.
	* i386-tbl.h: Likewise.