use inferred NameNode type for builtin types instead of more generic entry type

Cython/Compiler/ExprNodes.py

@@ -1755,6 +1755,10 @@ class NameNode(AtomicExprNode):
         self.check_identifier_kind()
         entry = self.entry
         type = entry.type
+        if (type.is_pyobject and self.inferred_type and
+                self.inferred_type.is_builtin_type):
+            # assume that type inference is smarter than the static entry
+            type = self.inferred_type
         self.type = type
 
     def check_identifier_kind(self):

tests/run/py_ucs4_type.pyx

@@ -252,6 +252,23 @@ def iter_and_in():
         if c in u'abCDefGh':
             print c
 
+
+#@cython.test_fail_if_path_exists('//ForInStatNode')
+def iter_inferred():
+    """
+    >>> iter_inferred()
+    a
+    b
+    c
+    d
+    e
+    """
+    uchars = list(u"abcde")
+    uchars = u''.join(uchars)
+    for c in uchars:
+        print c
+
+
 @cython.test_assert_path_exists('//SwitchStatNode',
                                 '//ForFromStatNode')
 @cython.test_fail_if_path_exists('//ForInStatNode')