x86/insn: x86/insn: Add support for REX2 prefix to the instruction decoder opcode map

Support for REX2 has been added to the instruction decoder logic and the
awk script that generates the attribute tables from the opcode map.

Add REX2 prefix byte (0xD5) to the opcode map.

Add annotation (!REX2) for map 0/1 opcodes that are reserved under REX2.

Add JMPABS to the opcode map and add annotation (REX2) to identify that it
has a mandatory REX2 prefix. A separate opcode attribute table is not
needed at this time because JMPABS has the same attribute encoding as the
MOV instruction that it shares an opcode with i.e. INAT_MOFFSET.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240502105853.5338-7-adrian.hunter@intel.com