Delegate opcodes to select disassembler in GDB

Delegate opcodes to select disassembler in GDB

This patch changes GDB to use disassembler selected by opcodes in
default, so that we don't have to duplicate the selection logic again
in GDB side.  For example, gdb/score-tdep.c has

static int
score_print_insn (bfd_vma memaddr, struct disassemble_info *info)
{
  if (info->endian == BFD_ENDIAN_BIG)
    return print_insn_big_score (memaddr, info);
  else
    return print_insn_little_score (memaddr, info);
}

and opcodes/disassemble.c has the same logic,

    case bfd_arch_score:
      if (big)
	disassemble = print_insn_big_score;
      else
	disassemble = print_insn_little_score;

This patch removes the logic in GDB and calls
opcodes/disassemble.c:disassembler in default to select disassembler.

gdb:

2017-05-24  Yao Qi  <yao.qi@linaro.org>

	* alpha-tdep.c (alpha_gdbarch_init): Don't call
	set_gdbarch_print_insn.
	* arc-tdep.c (arc_gdbarch_init): Likewise.
	* arch-utils.c: include dis-asm.h.
	(default_print_insn): New function.
	* arch-utils.h (default_print_insn): Declare.
	* avr-tdep.c (avr_gdbarch_init): Don't call set_gdbarch_print_insn.
	* bfin-tdep.c (bfin_gdbarch_init): Likewise.
	* cris-tdep.c (cris_delayed_get_disassembler): Remove.
	(cris_gdbarch_init): Don't call set_gdbarch_print_insn.
	* frv-tdep.c (frv_gdbarch_init): Likewise.
	* ft32-tdep.c (ft32_gdbarch_init): Likewise.
	* gdbarch.sh (print_insn): Use default_print_insn.
	* gdbarch.c: Regenerated.
	* hppa-tdep.c (hppa_gdbarch_init): Likewise.
	* iq2000-tdep.c (iq2000_gdbarch_init): Likewise.
	* lm32-tdep.c (lm32_gdbarch_init): Likewise.
	* m32c-tdep.c (m32c_gdbarch_init): Likewise.
	* m32r-tdep.c (m32r_gdbarch_init): Likewise.
	* m68hc11-tdep.c (gdb_print_insn_m68hc11): Remove.
	(m68hc11_gdbarch_init): Don't call set_gdbarch_print_insn.
	* m68k-tdep.c (m68k_gdbarch_init): Likewise.
	* m88k-tdep.c (m88k_gdbarch_init): Likewise.
	* microblaze-tdep.c (microblaze_gdbarch_init): Likewise.
	* mn10300-tdep.c (mn10300_gdbarch_init): Likewise.
	* moxie-tdep.c (moxie_gdbarch_init): Likewise.
	* msp430-tdep.c (msp430_gdbarch_init): Likewise.
	* mt-tdep.c (mt_gdbarch_init): Likewise.
	* nds32-tdep.c (nds32_gdbarch_init): Likewise.
	* nios2-tdep.c (nios2_print_insn): Remove.
	(nios2_gdbarch_init): Don't call set_gdbarch_print_insn.
	* rx-tdep.c (rx_gdbarch_init): Likewise.
	* s390-linux-tdep.c (s390_gdbarch_init): Likewise.
	* score-tdep.c (score_print_insn): Remove.
	(score_gdbarch_init): Don't call set_gdbarch_print_insn.
	* sh-tdep.c (sh_gdbarch_init): Likewise.
	* sh64-tdep.c (sh64_gdbarch_init): Likewise.
	* sparc-tdep.c (sparc32_gdbarch_init): Likewise.
	* tic6x-tdep.c (tic6x_print_insn): Remove.
	(tic6x_gdbarch_init): Don't call set_gdbarch_print_insn.
	* tilegx-tdep.c (tilegx_gdbarch_init): Likewise.
	* v850-tdep.c (v850_gdbarch_init): Likewise.
	* vax-tdep.c (vax_gdbarch_init): Likewise.
	* xstormy16-tdep.c (xstormy16_gdbarch_init): Likewise.
	* xtensa-tdep.c (xtensa_gdbarch_init): Likewise.