fixes #427, static fields emitted outside the scope of their class

lib/runtime/dart/_interceptors.js

 dart_library.library('dart/_interceptors', null, /* Imports */[
   'dart/_runtime',
   'dart/core',
   'dart/_internal',
   'dart/collection',
   'dart/math'
 ], /* Lazy imports */[
   'dart/_js_helper'
 ], function(exports, dart, core, _internal, collection, math, _js_helper) {
   'use strict';
@@ skipping 852 matching lines @@
       _handleIEtoString: [core.String, [core.String]],
       _bitCount: [core.int, [core.int]],
       _shru: [core.int, [core.int, core.int]],
       _shrs: [core.int, [core.int, core.int]],
       _ors: [core.int, [core.int, core.int]],
       _spread: [core.int, [core.int]]
     }),
     names: ['_handleIEtoString', '_bitCount', '_shru', '_shrs', '_ors', '_spread']
   });
   JSNumber[dart.metadata] = () => [dart.const(new _js_helper.JsPeerInterface({name: 'Number'}))];
-  dart.registerExtension(dart.global.Number, JSNumber);
   JSNumber._MIN_INT32 = -2147483648;
   JSNumber._MAX_INT32 = 2147483647;
+  dart.registerExtension(dart.global.Number, JSNumber);
   const _defaultSplit = Symbol('_defaultSplit');
   dart.defineExtensionNames([
     'codeUnitAt',
     'allMatches',
     'matchAsPrefix',
     '+',
     'endsWith',
     'replaceAll',
     'replaceAllMapped',
     'splitMapJoin',
@@ skipping 535 matching lines @@
   exports.JSString = JSString;
   exports.getInterceptor = getInterceptor;
   exports.JSBool = JSBool;
   exports.JSIndexable = JSIndexable;
   exports.JSMutableIndexable = JSMutableIndexable;
   exports.JSObject = JSObject;
   exports.JavaScriptObject = JavaScriptObject;
   exports.PlainJavaScriptObject = PlainJavaScriptObject;
   exports.UnknownJavaScriptObject = UnknownJavaScriptObject;
 });