opcodes:

opcodes:
	* ppc-opc.c (MO): Make optional.
	(RAO, RSO, SHO): New optional forms of RA, RS, SH operands.
	(tlbwe): Accept for both PPC403 and BOOKE.  Make all operands optional.
gas:
	* tc-ppc.c (md_assemble): Rewrite comment about optional operands
	to indicate that 'all or none' is also handled.  Pluralize a
	word in another comment.
gas/testsuite:
	* gas/ppc/booke.s: Add two more forms of the mbar instruction
	and three forms of the tlbwe instruction.
	* gas/ppc/booke.d: Update to match.