* tm-sparc.c (EXTRA_FRAME_INFO): New field sp_offset.

	* tm-sparc.c (EXTRA_FRAME_INFO): New field sp_offset.
	* sparc-tdep.c (sparc_init_extra_frame_info): Set it.
	(examine_prologue, sparc_init_extra_frame_info): Use ->frame plus
	->sp_offset to compute the address something is saved at, not
	->bottom.

	* sparc-tdep.c (get_saved_register): New function.
	* tm-sparc.h: Define GET_SAVED_REGISTER; don't define
	FRAME_FIND_SAVED_REGS, HAVE_REGISTER_WINDOWS or REGISTER_IN_WINDOW_P.
	* stack.c (frame_info): Add comment about what to do if
	FRAME_FIND_SAVED_REGS is not defined.

	* sparc-tdep.c (sparc_init_extra_frame_info): Set ->frame field
	here.  Get it right for flat frames.
	* sparc-tdep.c (sparc_frame_chain): Instead of returning
	meaningful value for ->frame field, just return dummy value.
	This change is needed because the old code didn't deal with mixed
	flat and non-flat frames.

	* sparc-tdep.c (sparc_pop_frame): Write SP_REGNUM from
	frame->frame, don't go through saved regs for this.

	* sparc-tdep.c: Move guts of skip_prologue to new function
	examine_prologue.  Check for flat prologue and set is_flat.
	Provide the caller with the information about what is saved where
	if desired.
	(skip_prologue, sparc_frame_find_saved_regs): Call examine_prologue.

	* sparc-tdep.c: Replace union sparc_insn_layout and anonymous
	union in isannulled, which won't work on a little-endian host,
	with X_* macros.

	* sparc-tdep.c (sparc_frame_saved_pc): If addr == 0, the saved PC
	is still in %o7.

	* config/sparc/tm-sparc.h: Define INIT_FRAME_PC and
	INIT_FRAME_PC_FIRST.
	* blockframe.c (get_prev_frame_info): Modify comments regarding
	INIT_FRAME_PC_FIRST and the sparc.

	* sparc-tdep.c (single_step): Use 4 not sizeof (long) for size of
	instruction.