* sparc-linux-tdep.c (sparc32_linux_sigtramp_p): Fix

	* sparc-linux-tdep.c (sparc32_linux_sigtramp_p): Fix
	signal return stub symbol names, __restore and __restore_rt are
	the i386 symbol names not the sparc ones.
	(sparc32_linux_sigtramp_frame_cache): Document bits/sigcontext.h
	as where the offsets were obtained from.
	* sparc64-linux-tdep.c (LINUX64_RT_SIGTRAMP_INSN0,
	LINUX64_RT_SIGTRAMP_INSN1): New defines.
	(sparc64_linux_sigtramp_start, sparc64_linux_sigtramp_p,
	sparc64_linux_sigtramp_frame_cache,
	sparc64_linux_sigtramp_frame_this_id,
	sparc64_linux_sigtramp_frame_prev_register,
	sparc64_linux_sigtramp_frame_sniffer): New functions.
	(sparc64_linux_sigtramp_frame_unwind): New frame unwinder.
	(sparc64_linux_init_abi): Register sigtramp frame sniffer.
	* Makefile.in (sparc64-linux-tdep.o): Update dependencies.