More fixes for memory access violations whilst scanning corrupt binaries.

More fixes for memory access violations whilst scanning corrupt binaries.

	PR binutils/17512
	* config/obj-coff.c (coff_obj_symbol_new_hook): Set the is_sym
	field.

	* coffcode.h (coff_ptr_struct): Add is_sym field.
	(coff_new_section_hook): Set the is_sym field.
	(coff_pointerize_aux_hook): Check the is_sym field.
	(coff_print_aux): Likewise.
	(coff_compute_section_file_positions): Likewise.
	(coff_write_object_contents): Likewise.
	(coff_slurp_line_table): Likewise.
	(coff_slurp_symbol_table): Likewise.
	(CALC_ADDEND): Likewise.
	* coffgen.c (coff_renumber_symbols): Likewise.
	(coff_mangle_symbols): Likewise.
	(coff_fix_symbol_name): Likewise.
	(coff_write_symbol): Likewise.
	(coff_write_alien_symbol): Likewise.
	(coff_write_native_symbol): Likewise.
	(coff_write_symbols): Likewise.
	(coff_write_linenumbers): Likewise.
	(coff_pointerize_aux): Likewise.
	(coff_get_normalized_symtab): Likewise.
	(coff_get_symbol_info): Likewise.
	(bfd_coff_get_syment): Likewise.
	(bfd_coff_get_auxent): Likewise.
	(coff_print_symbol): Likewise.
	(coff_find_nearest_line_with_names): Likewise.
	(bfd_coff_set_symbol_class): Likewise.
	(coff_make_empty_symbol): Set the is_sym field.
	(coff_bfd_make_debug_symbol): Likewise.
	* peicode.h (pe_ILF_make_a_symbol): Likewise.
	* libcoff.h: Regenerate.
	* libcoff-in.h: Regenerate.