Backport from mainline.

	Backport from mainline.

	gas/
	* config/tc-arm.c (parse_operands): Handle invalid register name
	for OP_RIWR_RIWC.

	gas/testsuite/
	* gas/arm/iwmmxt-bad.s: Test invalid register names for wldrw and
	wstrw.
	* gas/arm/iwmmxt-bad.l: Update.

	gas/
	* config/tc-arm.c (enum operand_parse_code): Add OP_RIWC_RIWG.
	(parse_operands): Handle it.
	(insns): Use it for tmcr and tmrc.

	gas/testsuite/
	* gas/arm/iwmmxt.s: Test tmcr and tmrc with wcgr registers.
	* gas/arm/iwmmxt.d: Update.