* cgen-asm.c (build_asm_hash_table): Traverse compiled in table using

	* cgen-asm.c (build_asm_hash_table): Traverse compiled in table using
	table provided entry size.  Use CGEN_INSN_MNEMONIC.
	(cgen_parse_keyword): Rewrite.
	* cgen-dis.c (build_dis_hash_table): Traverse compiled in table using
	table provided entry size.  Use CGEN_INSN_MASK_BITSIZE.
	* cgen-opc.c: Clean up pass over `struct foo' usage.
	(cgen_keyword_lookup_value): Handle "" entry.
	(cgen_keyword_add): Likewise.