* gdb.t02/whatis.exp, gdb.t08/opaque.exp: Add XFAILs for

	* gdb.t02/whatis.exp, gdb.t08/opaque.exp:  Add XFAILs for
	sequent dynix.
	* gdb.t06/signals.exp:  Add clear_xfail for sequent dynix.
	* gdb.t15/funcargs.exp:  Conditionally step again to really
	finish from marker_call_with_trampolines. Handle the case where
	the first step from within call_with_trampolines already steps
	us back to main.
	* gdb.t15/gdbme.c:  Add comment to closing brace of
	call_with_trampolines for funcargs.exp.