* gdb.base/a1-selftest.exp (do_steps_and_nexts): Reinitialize source

	* gdb.base/a1-selftest.exp (do_steps_and_nexts):  Reinitialize source
	directory to search gdb directory. Accept and step over conditional
	stack alignment code. Consume $prompt in failure cases.
	Reset timeout to $oldtimeout instead of some arbitrary value.
	* gdb.base/nodebug.exp:  Limit backtrace to 10 frames to avoid
	timeout problems with infinite stack backtraces.
	* gdb.base/ptype.exp (ptype struct link, union tu_link):
	Accept function parameters for linkfunc member.