fix crash when calling non-trivial type constructors

Cython/Compiler/ExprNodes.py

@@ -2471,7 +2471,9 @@ class SimpleCallNode(CallNode):
             self.arg_tuple = TupleNode(self.pos, args = self.args)
             self.arg_tuple.analyse_types(env)
             self.args = None
-            if func_type is Builtin.type_type and function.entry.is_builtin and \
+            if func_type is Builtin.type_type and function.is_name and \
+                   function.entry and \
+                   function.entry.is_builtin and \
                    function.entry.name in Builtin.types_that_construct_their_instance:
                 # calling a builtin type that returns a specific object type
                 if function.entry.name == 'float':

tests/run/clone_type.pyx

+cdef class MyType:
+    def dup(self):
+        """
+        >>> x1 = MyType()
+        >>> isinstance(x1, MyType)
+        True
+        >>> x2 = x1.dup()
+        >>> isinstance(x2, MyType)
+        True
+        >>> x1 != x2
+        True
+        """
+        cdef MyType clone = <MyType>type(self)()
+        return clone