The x86 instruction decoder is used for both kernel instructions and
user space instructions (e.g. uprobes, perf tools Intel PT), so it is
good to update it with new instructions.

Add AVX512-FP16 instructions to x86 instruction decoder.

Note the EVEX map field is extended by 1 bit, and most instructions are in
map 5 and map 6.

Reference:
Intel AVX512-FP16 Architecture Specification
June 2021
Revision 1.0
Document Number: 347407-001US

Example using perf tools' x86 instruction decoder test:

  $ perf test -v "x86 instruction decoder" |& grep vfcmaddcph | head -2
  Decoded ok: 62 f6 6f 48 56 cb           vfcmaddcph %zmm3,%zmm2,%zmm1
  Decoded ok: 62 f6 6f 48 56 8c c8 78 56 34 12    vfcmaddcph 0x12345678(%eax,%ecx,8),%zmm2,%zmm1
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20211202095029.2165714-7-adrian.hunter@intel.com