[MIPS] Add Loongson 3A2000/3A3000 proccessor support.

[MIPS] Add Loongson 3A2000/3A3000 proccessor support.

bfd/
	* archures.c (bfd_architecture): New machine
	bfd_mach_mips_gs464e.
	* bfd-in2.h (bfd_architecture): Likewise.
	* cpu-mips.c (enum I_xxx): Likewise.
	(arch_info_struct): Likewise.
	* elfxx-mips.c (_bfd_elf_mips_mach): Handle
	E_MIPS_MACH_GS464E.
	(mips_set_isa_flags): Likewise.
	(mips_mach_extensions): Map bfd_mach_mips_gs464e to
	bfd_mach_mips_gs464 extension.

binutils/
	* NEWS: Mention Loongson 3A2000/3A3000 proccessor support.
	* readelf.c (get_machine_flags): Handle gs464e.

elfcpp/
	* mips.c (EF_MIPS_MACH): New E_MIPS_MACH_GS464E.

gas/
	* config/tc-mips.c (ISA_HAS_ODD_SINGLE_FPR): Exclude CPU_GS464E.
	(mips_cpu_info_table): Add gs464e descriptors.
	* doc/as.texi (march table): Add gs464e.

include/
	* elf/mips.h (E_MIPS_MACH_XXX): New E_MIPS_MACH_GS464E.
	* opcode/mips.h (CPU_XXX): New CPU_GS464E.

ld/
	* testsuite/ld-mips-elf/mips-elf-flags.exp: Run good_combination
	gs464e and gs464.

opcodes/
	* mips-dis.c (mips_arch_choices): Add gs464e descriptors.