Remove cleanups from solib-target.c
This removes the remaining cleanups from solib-target.c, plus a VEC, by using std::vector and std::unique_ptr. Tested by the buildbot. gdb/ChangeLog 2019-01-17 Tom Tromey <email@example.com> * solib-target.c (lm_info_target_p): Remove typedef. Don't declare VEC. (solib_target_parse_libraries): Change return type. (library_list_start_segment, library_list_start_section) (library_list_end_library, library_list_start_library); Update. (solib_target_free_library_list): Remove. (solib_target_parse_libraries): Remove cleanup. Change return type. (solib_target_current_sos): Update.