Fix power operation, fixes #1268

jedi/evaluate/syntax_tree.py

@@ -84,7 +84,7 @@ def eval_node(context, element):
             had_await = True
             first_child = children.pop(0)
 
-        context_set = eval_atom(context, first_child)
+        context_set = context.eval_node(first_child)
         for trailer in children:
             if trailer == '**':  # has a power operation.
                 right = context.eval_node(children[1])

test/completion/precedence.py

@@ -57,6 +57,11 @@ a
 #? int() str()
 (3 ** 'a')
 
+class X():
+    foo = 2
+#? int()
+(X.foo ** 3)
+
 # -----------------
 # assignments
 # -----------------