* rs6000-tdep.c (frame_saved_pc): Check for signal handler caller

	* rs6000-tdep.c (frame_saved_pc):  Check for signal handler caller
	before trying to determine the start of the function.
	(skip_prologue):  Skip subroutine call which might save the
	floating point registers only if it is within the first three
	instructions.
	Reinstate setting of alloca_reg if setup of a gcc frame pointer
	is found.
	(frame_get_cache_fsr):  Use new fields in rs6000_framedata.