Enhance the RX disassembler to detect and report bad instructions.

Enhance the RX disassembler to detect and report bad instructions.

opcode	* rx.h (enum RX_Size): Add RX_Bad_Size entry.

opcodes	* rx-decode.opc (bwl): Use RX_Bad_Size.
	(sbwl): Likewise.
	(ubwl): Likewise.  Rename to ubw.
	(uBWL): Rename to uBW.
	Replace all references to uBWL with uBW.
	* rx-decode.c: Regenerate.
	* rx-dis.c (size_names): Add entry for RX_Bad_Size.
	(opsize_names): Likewise.
	(print_insn_rx): Detect and report RX_Bad_Size.