Use new size-independent elf internal data structures.

Use new size-independent elf internal data structures.
(put_word, get_word): Define as appropriate for architecture word size.
Structure swapping functions changed to use them as appropriate.
(bfd_add_to_strtab): Now static.
(sym_is_global): New function.
(elf_map_symbols): Call it.  Now returns void.  Removed unused local variable.
(bfd_section_from_shdr): Mark string tables other than for section and symbol
names as normal sections having contents.
(fix_up_strtabs): New function; fixes up ELF header fields for stab sections
with string tables associated.
(elf_write_object_contents): Map fix_up_strtabs over all BFD sections.
Reordered condition tests for symbol flags; default to local-object value
instead of global-object.
(elf_symbol_from_bfd_symbol): Hid conditionally-used variable inside condition
test.
(elf_print_symbol): Use fprintf_vma.
(elf_idx_of_sym, bfd_shdr_from_section): Unused functions commented out.