Prevent a memory exhaustion failure when running objdump on a fuzzed input file with...

Prevent a memory exhaustion failure when running objdump on a fuzzed input file with corrupt string and attribute sections.

	PR 22809
	* elf.c (bfd_elf_get_str_section): Check for an excessively large
	string section.
	* elf-attrs.c (_bfd_elf_parse_attributes): Issue an error if the
	attribute section is larger than the size of the file.