Fix ECOFF objcopy to actually copy debugging information.

	Fix ECOFF objcopy to actually copy debugging information.
	* ecoff.c (ecoff_bfd_copy_private_bfd_data): New function.
	(ecoff_get_extr): Assume that any ECOFF symbol with local clear is
	an external symbol, rather than checking the symbol flags.  Only
	check the flags for non-ECOFF symbols.
	* ecofflink.c (bfd_ecoff_debug_externals): Don't crash if the
	output_section field of the symbol section is NULL.
	* libecoff.h (ecoff_bfd_copy_private_bfd_data): Declare as
	function rather than defining as macro.