* solib-svr4.c: Update copyright year. Include "gdb_assert.h".

* solib-svr4.c: Update copyright year.  Include "gdb_assert.h".
(SVR4_FETCH_LINK_MAP_OFFSETS): Don't define if not already
defined.
(legacy_fetch_link_map_offsets): Remove prototype.
(fetch_link_map_offsets_gdbarch_data): Remove.
(LM_ADDR, LM_NEXT, IGNORE_FIRST_LINK_MAP_ENTRY)
(first_link_map_member, open_symbol_file_object, svr4_current_sos)
(svr4_fetch_objfile_link_map): Call svr4_fetch_link_map_offsets
instead of SVR4_FETCH_LINK_MAP_OFFSETS.
(solib_svr4_data): New variable.
(struct solib_svr4_ops): New.
(solib_svr4_init): New fynction.
(legacy_fetch_link_map_offsets, init_fetch_link_map_offsets):
Remove functions.
(svr4_fetch_link_map_offsets, svr4_have_link_map_offsets): Rewrite
using the new `struct solib_svr4_ops'.
(_initialize_svr4_solib): Replace registration of per-architecture
data.  Add temporary hack to set
svr4_legacy_fetch_link_map_offsets if SVR4_FETCH_LINK_MAP_OFFSETS
is set.
* Makefile.in (solib-svr4.o): Update dependencies.