* config/mips/mips.h (enum reg_class): Add FRAME_REGS.
	(REG_CLASS_NAMES): Update.
	(REG_CLASS_CONTENTS): Update.
	* config/mips/mips.c (mips_regno_to_class): Use FRAME_REGS instead
	of ALL_REGS for regs 77 and 78.
	* function.c (instantiate_virtual_regs_in_insn): Assert that
	return value of simplify_gen_subreg is not NULL.

testsuite:
	* gcc.c-torture/compile/20080903-1.c: New test.

From-SVN: r140035