* config/rs6000/tm-rs6000.h (INIT_EXTRA_FRAME_INFO):

	* config/rs6000/tm-rs6000.h (INIT_EXTRA_FRAME_INFO):
	Don't test for zero backchain pointer to recognize a signal
	handler frame, if read() gets interrupted by a signal, the
	backchain will be non zero.
	(SIG_FRAME_FP_OFFSET):  Move to here from rs6000-tdep.c,
	improve comment.
	(SIG_FRAME_PC_OFFSET):  New definition.
	(FRAME_SAVED_PC):  Return saved pc from sigcontext if this
	is a signal handler frame.
	* rs6000-tdep.c (function_frame_info):  Do not error out
	if we can't access the instructions.

	* config/rs6000/tm-rs6000.h (CONVERT_FROM_FUNC_PTR_ADDR):
	New definition to get the function address from a function pointer.
	* valops.c (find_function_addr):  Use it when calling a user
	function through a function pointer.