Remove any ordering from a nested select query (in the where-clause).

This fixes r9701 for Oracle (the test introduced there did its job and failed
previously).

git-svn-id: http://code.djangoproject.com/svn/django/trunk@9714 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/sql/query.py

@@ -317,11 +317,13 @@ class BaseQuery(object):
         """
         Perform the same functionality as the as_sql() method, returning an
         SQL string and parameters. However, the alias prefixes are bumped
-        beforehand (in a copy -- the current query isn't changed).
+        beforehand (in a copy -- the current query isn't changed) and any
+        ordering is removed.
 
         Used when nesting this query inside another.
         """
         obj = self.clone()
+        obj.clear_ordering(True)
         obj.bump_prefix()
         return obj.as_sql()