Reverted "Refs #20939 -- Moved subquery ordering clearing optimizatio…

…n to the __in lookup."

This reverts commit e62ea0b since it
broke multi-column __in lookups and _meta.order_wrt on Oracle.

django/db/models/lookups.py

@@ -367,18 +367,9 @@ def process_rhs(self, compiler, connection):
             placeholder = '(' + ', '.join(sqls) + ')'
             return (placeholder, sqls_params)
         else:
-            from django.db.models.sql.query import Query  # avoid circular import
-            if isinstance(self.rhs, Query):
-                query = self.rhs
-                # It's safe to drop ordering if the queryset isn't using
-                # slicing, distinct(*fields), or select_for_update().
-                if (query.low_mark == 0 and query.high_mark is None and
-                        not query.distinct_fields and
-                        not query.select_for_update):
-                    query.clear_ordering(True)
-                if not query.has_select_fields:
-                    query.clear_select_clause()
-                    query.add_fields(['pk'])
+            if not getattr(self.rhs, 'has_select_fields', True):
+                self.rhs.clear_select_clause()
+                self.rhs.add_fields(['pk'])
             return super().process_rhs(compiler, connection)
 
     def get_rhs_op(self, connection, rhs):

django/db/models/sql/query.py

@@ -981,6 +981,12 @@ def resolve_expression(self, query, *args, **kwargs):
         # Subqueries need to use a different set of aliases than the outer query.
         clone.bump_prefix(query)
         clone.subquery = True
+        # It's safe to drop ordering if the queryset isn't using slicing,
+        # distinct(*fields) or select_for_update().
+        if (self.low_mark == 0 and self.high_mark is None and
+                not self.distinct_fields and
+                not self.select_for_update):
+            clone.clear_ordering(True)
         return clone
 
     def prepare_lookup_value(self, value, lookups, can_reuse, allow_joins=True):