* solib-svr4.h (struct link_map_offsets): Remove r_debug_size and

* solib-svr4.h (struct link_map_offsets): Remove r_debug_size and
r_map_size members.  Add r_version_offset, r_version_size and
r_ldsomap_offset members.
* solib-svr4.c (solib_svr4_r_map): Renamed from
fetch_link_map_member.  Simplify using read_memory_typed_address.
(solib_svr4_r_ldsomap): New function.
(open_symbol_file_object): Use solib_svr_r_map.
(svr4_current_sos): Use solib_svr4_r_map and look for the dynamic
linker by using solib_svr4_r_ldsomap.
(svr4_ilp32_fetch_link_map_offsets)
(svr4_lp64_fetch_link_map_offsets): Adjust for changes to `struct
link_map_offsets'.
* solib-legacy.c (legacy_svr4_fetch_link_map_offsets): Adjust for
changes to `struct link_map_offsets'.
* mipsnbsd-tdep.c (mipsnbsd_ilp32_fetch_link_map_offsets)
(mipsnbsd_lp64_fetch_link_map_offsets): Adjust for changes to
`struct link_map_offsets'.