Remove more shifts for sign/zero extension

cpu/
	* epiphany.cpu (f-sdisp11): Don't sign extend with shifts.
	* lm32.cpu (f-branch, f-vall): Likewise.
	* m32.cpu (f-lab-8-16): Likewise.
opcodes/
	* arc-dis.c (BITS): Don't truncate high bits with shifts.
	* nios2-dis.c (nios2_print_insn_arg): Don't sign extend with shifts.
	* tic54x-dis.c (print_instruction): Likewise.
	* tilegx-opc.c (parse_insn_tilegx): Likewise.
	* tilepro-opc.c (parse_insn_tilepro): Likewise.
	* visium-dis.c (disassem_class0): Likewise.
	* pdp11-dis.c (sign_extend): Likewise.
	(SIGN_BITS): Delete.
	* epiphany-ibld.c: Regenerate.
	* lm32-ibld.c: Regenerate.
	* m32c-ibld.c: Regenerate.