* elf-bfd.h (elf_string_from_elf_strtab): Delete macro.
* elf.c (bfd_elf_string_from_elf_section): Expand occurrence of
elf_string_from_elf_strtab.
(_bfd_elf_setup_group_pointers, bfd_section_from_shdr): Likewise.
(bfd_section_from_shdr): For SHT_SYMTAB, load SHT_SYMTAB_SHNDX too
if it exists. Don't do the reverse for SHT_SYMTAB_SHNDX. For
SHT_STRTAB, check whether the strtab is for symtab or dynsymtab by
looking at cached symtab info first, before iterating over headers.
For SHT_REL and SHT_RELA, load dynsymtab if needed.
* elfcode.h (elf_object_p): Don't load section header stringtab