Add support for Loongson 3A2000/3A3000 processor.

Add support for Loongson 3A2000/3A3000 processor.

gcc/
	* config/mips/gs464e.md: New.
	* config/mips/mips-cpus.def: Define gs464e.
	* config/mips/mips-tables.opt: Regenerate.
	* config/mips/mips.c (mips_rtx_cost_data): Add DEFAULT_COSTS for
	gs464e.
	(mips_issue_rate): Add support for gs464e.
	(mips_multipass_dfa_lookahead): Likewise.
	(mips_option_override): Enable MMI, EXT and EXT2 for gs464e.
	* config/mips/mips.h: Define TARGET_GS464E and TUNE_GS464E.
	(MIPS_ISA_LEVEL_SPEC): Infer mips64r2 from gs464e.
	(ISA_HAS_FUSED_MADD4): Enable for TARGET_GS464E.
	(ISA_HAS_UNFUSED_MADD4): Exclude TARGET_GS464E.
	* config/mips/mips.md: Include gs464e.md.
	(processor): Add gs464e.
	* doc/invoke.texi: Add gs464e to supported architectures.

From-SVN: r265866