sparc.c (sparc_frame_info): Combine members gp_sp_offset and fp_sp_offset into reg_offset.

	* sparc.c (sparc_frame_info): Combine members gp_sp_offset and
	fp_sp_offset into reg_offset.  All uses changed.
	(RETURN_ADDR_REGNUM): New macro.
	(RETURN_ADDR_MASK, FRAME_POINTER_MASK): New macros.
	(sparc_flat_compute_frame_info): Rename local mask to gmask.
	Only ensure reg save area is 8 byte aligned if necessary.
	(sparc_flat_save_restore): New arguments base_reg, offset, gmask,
	and fmask.  All callers changed.  No longer use %g2 to save regs
	in big stack frame.
	(sparc_flat_output_function_prologue): Delete local tsize.
	Reorder storing of previous frame pointer and return address reg to
	make it easier for gdb to identify flat functions.  Decrement %sp
	twice when saving call-saved regs in big frames.
	(sparc_flat_output_function_epilogue): Likewise when restoring
	call-saved regs.

From-SVN: r8310