test suite update - gdb.base/[t-z]

test suite update - gdb.base/[t-z]

Convert files gdb.base/[t-z]*.exp to use standard_output_file et al.

	* gdb.base/testenv.exp, gdb.base/tui-layout.exp,
	gdb.base/twice.exp, gdb.base/type-opaque.exp, gdb.base/unload.exp,
	gdb.base/unwindonsignal.exp, gdb.base/valgrind-db-attach.exp,
	gdb.base/valgrind-infcall.exp, gdb.base/value-double-free.exp,
	gdb.base/varargs.exp, gdb.base/watch-cond-infcall.exp,
	gdb.base/watch-cond.exp, gdb.base/watch-non-mem.exp,
	gdb.base/watch-read.exp, gdb.base/watch-vfork.exp,
	gdb.base/watch_thread_num.exp, gdb.base/watchpoint-cond-gone.exp,
	gdb.base/watchpoint-delete.exp, gdb.base/watchpoint-hw.exp,
	gdb.base/watchpoint-solib.exp, gdb.base/watchpoint.exp,
	gdb.base/watchpoints.exp, gdb.base/wchar.exp, gdb.base/whatis.exp:
	Use standard_testfile, standard_output_file, prepare_for_testing,
	clean_restart.