More fixes for invalid memory accesses triggered by fuzzed binaries.

More fixes for invalid memory accesses triggered by fuzzed binaries.

	PR binutils/17512
	* nm.c (print_symbol): Add 'is_synthetic' parameter.  Use it to
	help initialize the info.elfinfo field.
	(print_size_symbols): Add 'synth_count' parameter.  Use it to set
	the is_synthetic parameter when calling print_symbol.
	(print_symbols): Likewise.
	(display_rel_file): Pass synth_count to printing function.
	(display_archive): Break loop if the last archive displayed
	matches the current archive.
	* size.c (display_archive): Likewise.

	* archive.c (do_slurp_bsd_armap): Make sure that the parsed sized
	is at least big enough for the header to be read.
	* elf32-i386.c (elf_i386_get_plt_sym_val): Skip unknown relocs.
	* mach-o.c (bfd_mach_o_get_synthetic_symtab): Add range checks.
	(bfd_mach_o_read_command): Prevetn duplicate error messages about
	unrecognized commands.
	* syms.c (_bfd_stab_section_find_nearest_line): Add range checks
	when indexing into the string table.