* amd64-tdep.c: Add a frame unwinder for function epilogues.
	(amd64_in_function_epilogue_p): New function.
	(amd64_epilogue_frame_sniffer): New function.
	(amd64_epilogue_frame_cache): New function.
	(amd64_epilogue_frame_this_id): New function.
	(amd64_epilogue_frame_unwind): New struct frame_unwind.
	(amd64_init_abi): Hook the new unwinder.

	* amd64-linux-tdep.c (amd64_linux_init_abi): Set gdbarch to use
	SVR4 method for skip_trampoline_code.