* config.gcc (mipsisa32-*-elf*, mipsisa32el-*-elf*)
	(mipsisa32r2-*-elf*, mipsisa32r2el-*-elf*)
	(mipsisa64-*-elf*, mipsisa64el-*-elf*): Combine top-level
	stanzas.  Use the first part of the triplet to set MIPS_ISA_DEFAULT.
	Remove redundant setting of MASK_FLOAT64 and MASK_64BIT for the
	64-bit targets.  Add support for *-elfoabi*.
	* config/mips/t-isa3264 (MULTILIB_OPTIONS, MULTILIB_DIRNAMES): Use
	different settings if $(tm_defines) does not select the EABI.
	(MULTILIB_EXCLUSIONS): Define in those circumstances.
	* config/mips/mips.h (MIPS_ISA_LEVEL_OPTION_SPEC): New macro.
	(MIPS_ARCH_OPTION_SPEC): Likewise.
	(MIPS_ISA_LEVEL_SPEC): Likewise.
	(OPTION_DEFAULT_SPECS): Use MIPS_ARCH_OPTION_SPEC.
	* config/mips/elfoabi.h: New file.

From-SVN: r126195