Fix potential memory leaks in some of the binutils source files.
* rdcoff.c (parse_coff_struct_type): Free fields array upon early
exit.
(parse_coff_enum_type): Free names and vals arrays upon early
exit.
* rddbg.c (read_section_stabs_debugging_info): Free shandle and
strings and stabs arrays upon early exit.
* readelf.c (get_32bit_section_headers): Free shdrs structure upon
early exit.
(get_64bit_section_headers): Likewise.
(get_32bit_elf_symbols): Generate an error if multiple symbol
table index sections are associated with the same symbol section.
(get_64bit_elf_symbols): Likewise.
(process_dynamic_section): Generate an error if there are multiple
dynamic symbol table sections, multiple dynamic string tables or
multiple dynamic symbol information sections.