PR 67414 Better diagnostics on backtrace failure, gf_strerror bugfix

PR 67414 Better diagnostics on backtrace failure, gf_strerror bugfix

2015-09-02  Janne Blomqvist  <jb@gcc.gnu.org>

	PR libfortran/67414
	* io/write.c (gfc_itoa): Move to runtime/string.c.
	* libgfortran.h (show_backtrace): Make arg bool.
	(gfc_itoa): New prototype.
	* runtime/backtrace.c (struct mystate): Change type of try_simple
	field, add in_signal_handler field.
	(error_callback): Print out error number, or if not in a signal
	handler, the error message.
	(show_backtrace): Change type of arg, change initialization of
	struct mystate.
	(backtrace): Call show_backtrace with correct arg type.
	* runtime/compile_options.c (backtrace_handler): Call with correct
	arg type.
	* runtime/error.c (sys_abort): Likewise.
	(gf_strerror): Handle newlocale() failure.
	* runtime/string.c (gfc_itoa): Function moved here from
	io/write.c.

From-SVN: r227404