fixes #616, statics on callable functions

test/codegen_expected/language/regress_21793_test_none_multi.js

 dart_library.library('language/regress_21793_test_none_multi', null, /* Imports */[
   'dart_sdk'
 ], function load__regress_21793_test_none_multi(exports, dart_sdk) {
   'use strict';
   const core = dart_sdk.core;
   const dart = dart_sdk.dart;
   const dartx = dart_sdk.dartx;
   const regress_21793_test_none_multi = Object.create(null);
   let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
   regress_21793_test_none_multi.A = dart.callableClass(function A(...args) {
-    const self = this;
     function call(...args) {
-      return self.call.apply(self, args);
+      return call.call.apply(call, args);
     }
     call.__proto__ = this.__proto__;
     call.new.apply(call, args);
     return call;
   }, class A extends core.Object {
     call(x) {
       return x;
     }
   });
   dart.setSignature(regress_21793_test_none_multi.A, {
     methods: () => ({call: dart.definiteFunctionType(dart.dynamic, [dart.dynamic])})
   });
   regress_21793_test_none_multi.main = function() {
     core.print(dart.dcall(new regress_21793_test_none_multi.A(), 499));
   };
   dart.fn(regress_21793_test_none_multi.main, VoidTodynamic());
   // Exports:
   exports.regress_21793_test_none_multi = regress_21793_test_none_multi;
 });