(_bfd_elf_eh_frame_address_size): Declare.
* elfxx-target.h (elf_backend_eh_frame_address_size): Define a default.
(elfNN_bed): Initialize elf_backend_eh_frame_address_size.
* elfxx-mips.h (_bfd_mips_elf_eh_frame_address_size): Declare.
(elf_backend_eh_frame_address_size): Define.
* elfxx-mips.c (_bfd_mips_elf_eh_frame_address_size): New function.
* elf-eh-frame.c (_bfd_elf_discard_section_eh_frame): Get the address
size from the new backend hook.
(_bfd_elf_write_section_eh_frame): Likewise.
(_bfd_elf_eh_frame_address_size): New function.
