Add __file__, __doc__, __name__, __builtins__ to module globals.

Cython/Compiler/Symtab.py

@@ -821,6 +821,8 @@ class ModuleScope(Scope):
         self.cached_builtins = []
         self.undeclared_cached_builtins = []
         self.namespace_cname = self.module_cname
+        for name in ['__builtins__', '__name__', '__file__', '__doc__']:
+            self.declare_var(EncodedString(name), py_object_type, None)
     
     def qualifying_scope(self):
         return self.parent_module