Move search_ancestor to jedi.parser.tree.

jedi/parser/python/tree.py

@@ -30,17 +30,8 @@ See also :attr:`Scope.subscopes` and :attr:`Scope.statements`.
 from itertools import chain
 
 from jedi._compatibility import utf8_repr, unicode
-from jedi.parser.tree import Node, BaseNode, Leaf, ErrorNode, ErrorLeaf
-
-
-def search_ancestor(node, node_type_or_types):
-    if not isinstance(node_type_or_types, (list, tuple)):
-        node_type_or_types = (node_type_or_types,)
-
-    while True:
-        node = node.parent
-        if node is None or node.type in node_type_or_types:
-            return node
+from jedi.parser.tree import Node, BaseNode, Leaf, ErrorNode, ErrorLeaf, \
+    search_ancestor
 
 
 class DocstringMixin(object):