Revert 2017-08-28 Nathan Sidwell <nathan@acm.org>
Restore sorted_fields vector.
* cp-tree.h (lang_type): Restore sorted_fields vector.
(CLASSTYPE_SORTED_FIELDS): Restore.
(CLASSTYPE_BINDINGS): Delete.
* name-lookup.c (lookup_field_1): Restore binary search.
(sorted_fields_type_new, count_fields,
add_fields_to_record_type, add_enum_fields_to_record_type): Restore
(set_class_bindings): Revert.
(insert_late_enum_def_binding): Restore field_vec insertion.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@251592 138bc75d-0d04-0410-961f-82ee72b054a4