ubsan: crx: left shift cannot be represented in type 'int'

ubsan: crx: left shift cannot be represented in type 'int'

The ubsan complaint is fixed by the SBM change, with similar possible
complaints fixed by the EXTRACT change.  The rest is just cleanup.

include/
	* opcode/crx.h (inst <match>): Make unsigned int.
opcodes/
	* crx-dis.c (EXTRACT, SBM): Avoid signed overflow.
	(get_number_of_operands, getargtype, getbits, getregname),
	(getcopregname, getprocregname, gettrapstring, getcinvstring),
	(getregliststring, get_word_at_PC, get_words_at_PC, build_mask),
	(powerof2, match_opcode, make_instruction, print_arguments),
	(print_arg): Delete forward declarations, moving static to..
	(getregname, getcopregname, getregliststring): ..these definitions.
	(build_mask): Return unsigned int mask.
	(match_opcode): Use unsigned int vars.