There were several cases where the registers in the REX encoded range

There were several cases where the registers in the REX encoded range
got treated identically to the ones in the base range, due to not
paying attention to the fact that reg_entry's reg_num field doesn't
fully specify the register number (reg_flags also needs to be checked
for RegRex). This patch introduces and uses a new (inline) function to
obtain the full register number, and uses it to fix all those cases.

It additionally adds the missing operand checks for SVME instructions
(which match the monitor/mwait ones).

gas/
2012-08-07  Jan Beulich <jbeulich@suse.com>

	* config/tc-i386.c (register_number): New function.
	(build_vex_prefix, process_immext, process_operands,
	build_modrm_byte, i386_index_check): Use it.

gas/testsuite/
2012-08-07  Jan Beulich <jbeulich@suse.com>

	* gas/i386/x86-64-specific-reg.{s,l}: New.
	* gas/i386/i386.exp: Run new test.

opcodes/
2012-08-07  Jan Beulich <jbeulich@suse.com>

	* i386-opc.tbl: Remove "FIXME" comments from SVME instructions.