opcodes error messages

Another patch aimed at making binutils comply with the GNU coding
standard.  The generated files require
https://sourceware.org/ml/cgen/2018-q1/msg00004.html

cpu/
	* frv.opc: Include opintl.h.
	(add_next_to_vliw): Use opcodes_error_handler to print error.
	Standardize error message.
	(fr500_check_insn_major_constraints, frv_vliw_add_insn): Likewise.
opcodes/
	* sysdep.h (opcodes_error_handler): Define.
	(_bfd_error_handler): Declare.
	* Makefile.am: Remove stray #.
	* opc2c.c (main): Remove bogus -l arg handling.  Print "DO NOT
	EDIT" comment.
	* aarch64-dis.c, * arc-dis.c, * arm-dis.c, * avr-dis.c,
	* d30v-dis.c, * h8300-dis.c, * mmix-dis.c, * ppc-dis.c,
	* riscv-dis.c, * s390-dis.c, * sparc-dis.c, * v850-dis.c: Use
	opcodes_error_handler to print errors.  Standardize error messages.
	* msp430-decode.opc, * nios2-dis.c, * rl78-decode.opc: Likewise,
	and include opintl.h.
	* nds32-asm.c: Likewise, and include sysdep.h and opintl.h.
	* i386-gen.c: Standardize error messages.
	* msp430-decode.c, * rl78-decode.c, rx-decode.c: Regenerate.
	* Makefile.in: Regenerate.
	* epiphany-asm.c, * epiphany-desc.c, * epiphany-dis.c,
	* epiphany-ibld.c, * fr30-asm.c, * fr30-desc.c, * fr30-dis.c,
	* fr30-ibld.c, * frv-asm.c, * frv-desc.c, * frv-dis.c, * frv-ibld.c,
	* frv-opc.c, * ip2k-asm.c, * ip2k-desc.c, * ip2k-dis.c, * ip2k-ibld.c,
	* iq2000-asm.c, * iq2000-desc.c, * iq2000-dis.c, * iq2000-ibld.c,
	* lm32-asm.c, * lm32-desc.c, * lm32-dis.c, * lm32-ibld.c,
	* m32c-asm.c, * m32c-desc.c, * m32c-dis.c, * m32c-ibld.c,
	* m32r-asm.c, * m32r-desc.c, * m32r-dis.c, * m32r-ibld.c,
	* mep-asm.c, * mep-desc.c, * mep-dis.c, * mep-ibld.c, * mt-asm.c,
	* mt-desc.c, * mt-dis.c, * mt-ibld.c, * or1k-asm.c, * or1k-desc.c,
	* or1k-dis.c, * or1k-ibld.c, * xc16x-asm.c, * xc16x-desc.c,
	* xc16x-dis.c, * xc16x-ibld.c, * xstormy16-asm.c, * xstormy16-desc.c,
	* xstormy16-dis.c, * xstormy16-ibld.c: Regenerate.