test suite update - gdb.base/[cd]

test suite update - gdb.base/[cd]

Convert files gdb.base/[cd]*.exp to use standard_output_file et al.

	* call-ar-st.exp, call-rt-st.exp, call-sc.exp,
	call-signal-resume.exp, call-strs.exp, callexit.exp,
	callfuncs.exp, catch-load.exp, catch-syscall.exp, charset.exp,
	checkpoint.exp, chng-syms.exp, code-expr.exp, code_elim.exp,
	commands.exp, completion.exp, complex.exp, cond-expr.exp,
	condbreak.exp, consecutive.exp, constvars.exp, corefile.exp,
	ctxobj.exp, cursal.exp, cvexpr.exp, dbx.exp, default.exp,
	define.exp, del.exp, detach.exp, dfp-test.exp, display.exp,
	dmsym.exp, dump.exp, dup-sect.exp: Use standard_testfile,
	standard_output_file, prepare_for_testing, clean_restart.