fix some errors in our SDK, mostly around numbers

lib/runtime/dart/js.js

 dart_library.library('dart/js', null, /* Imports */[
   "dart_runtime/dart",
   'dart/core',
   'dart/collection',
   'dart/_js_helper'
 ], /* Lazy imports */[
 ], function(exports, dart, core, collection, _js_helper) {
   'use strict';
   let dartx = dart.dartx;
   dart.defineLazyProperties(exports, {
@@ skipping 10 matching lines @@
     static new(constructor, arguments$) {
       if (arguments$ === void 0)
         arguments$ = null;
       let ctor = constructor[_jsObject];
       if (arguments$ == null) {
         return dart.as(_wrapToDart(new ctor()), JsObject);
       }
       return dart.as(_wrapToDart(new ctor(...arguments$)), JsObject);
     }
     static fromBrowserObject(object) {
-      if (dart.is(object, core.num) || typeof object == 'string' || typeof object == 'boolean' || object == null) {
+      if (typeof object == 'number' || typeof object == 'string' || typeof object == 'boolean' || object == null) {
         dart.throw(new core.ArgumentError("object cannot be a num, string, bool, or null"));
       }
       return dart.as(_wrapToDart(_convertToJS(object)), JsObject);
     }
     static jsify(object) {
       if (!dart.is(object, core.Map) && !dart.is(object, core.Iterable)) {
         dart.throw(new core.ArgumentError("object must be a Map or Iterable"));
       }
       return dart.as(_wrapToDart(JsObject._convertDataTree(object)), JsObject);
     }
@@ skipping 16 matching lines @@
           convertedList[dartx.addAll](dart.as(dart.dsend(o, 'map', _convert), core.Iterable));
           return convertedList;
         } else {
           return _convertToJS(o);
         }
       }
       dart.fn(_convert);
       return _convert(data);
     }
     get(property) {
-      if (!(typeof property == 'string') && !dart.is(property, core.num)) {
+      if (!(typeof property == 'string') && !(typeof property == 'number')) {
         dart.throw(new core.ArgumentError("property is not a String or num"));
       }
       return _convertToDart(this[_jsObject][property]);
     }
     set(property, value) {
-      if (!(typeof property == 'string') && !dart.is(property, core.num)) {
+      if (!(typeof property == 'string') && !(typeof property == 'number')) {
         dart.throw(new core.ArgumentError("property is not a String or num"));
       }
       this[_jsObject][property] = _convertToJS(value);
       return value;
     }
     get hashCode() {
       return 0;
     }
     ['=='](other) {
       return dart.is(other, JsObject) && this[_jsObject] === dart.dload(other, _jsObject);
     }
     hasProperty(property) {
-      if (!(typeof property == 'string') && !dart.is(property, core.num)) {
+      if (!(typeof property == 'string') && !(typeof property == 'number')) {
         dart.throw(new core.ArgumentError("property is not a String or num"));
       }
       return property in this[_jsObject];
     }
     deleteProperty(property) {
-      if (!(typeof property == 'string') && !dart.is(property, core.num)) {
+      if (!(typeof property == 'string') && !(typeof property == 'number')) {
         dart.throw(new core.ArgumentError("property is not a String or num"));
       }
       delete this[_jsObject][property];
     }
     instanceof(type) {
       return this[_jsObject] instanceof _convertToJS(type);
     }
     toString() {
       try {
         return String(this[_jsObject]);
       } catch (e) {
         return super.toString();
       }
 
     }
     callMethod(method, args) {
       if (args === void 0)
         args = null;
-      if (!(typeof method == 'string') && !dart.is(method, core.num)) {
+      if (!(typeof method == 'string') && !(typeof method == 'number')) {
         dart.throw(new core.ArgumentError("method is not a String or num"));
       }
       if (args != null)
         args = core.List.from(args[dartx.map](_convertToJS));
       let fn = this[_jsObject][method];
       if (!(fn instanceof Function)) {
         dart.throw(new core.NoSuchMethodError(this[_jsObject], core.Symbol.new(dart.as(method, core.String)), args, dart.map()));
       }
       return _convertToDart(fn.apply(this[_jsObject], args));
     }
@@ skipping 72 matching lines @@
       }
       static _checkRange(start, end, length) {
         if (dart.notNull(start) < 0 || dart.notNull(start) > dart.notNull(length)) {
           dart.throw(new core.RangeError.range(start, 0, length));
         }
         if (dart.notNull(end) < dart.notNull(start) || dart.notNull(end) > dart.notNull(length)) {
           dart.throw(new core.RangeError.range(end, start, length));
         }
       }
       get(index) {
-        if (dart.is(index, core.num) && index == index[dartx.toInt]()) {
+        if (typeof index == 'number' && index == index[dartx.toInt]()) {
           this[_checkIndex](index);
         }
         return dart.as(super.get(index), E);
       }
       set(index, value) {
         dart.as(value, E);
-        if (dart.is(index, core.num) && index == index[dartx.toInt]()) {
+        if (typeof index == 'number' && index == index[dartx.toInt]()) {
           this[_checkIndex](index);
         }
         super.set(index, value);
         return value;
       }
       get length() {
         let len = this[_jsObject].length;
         if (typeof len === "number" && len >>> 0 === len) {
           return len;
         }
@@ skipping 98 matching lines @@
   let _dartObj = Symbol('_dartObj');
   class _DartObject extends core.Object {
     _DartObject(dartObj) {
       this[_dartObj] = dartObj;
     }
   }
   dart.setSignature(_DartObject, {
     constructors: () => ({_DartObject: [_DartObject, [dart.dynamic]]})
   });
   function _convertToJS(o) {
-    if (o == null || typeof o == 'string' || dart.is(o, core.num) || typeof o == 'boolean' || dart.notNull(_isBrowserType(o))) {
+    if (o == null || typeof o == 'string' || typeof o == 'number' || typeof o == 'boolean' || dart.notNull(_isBrowserType(o))) {
       return o;
     } else if (dart.is(o, core.DateTime)) {
       return _js_helper.Primitives.lazyAsJsDate(o);
     } else if (dart.is(o, JsObject)) {
       return dart.dload(o, _jsObject);
     } else if (dart.is(o, core.Function)) {
       return _putIfAbsent(exports._jsProxies, o, _wrapDartFunction);
     } else {
       return _putIfAbsent(exports._jsProxies, o, dart.fn(o => new _DartObject(o), _DartObject, [dart.dynamic]));
     }
   }
   dart.fn(_convertToJS);
   function _wrapDartFunction(f) {
     let wrapper = function() {
       let args = Array.prototype.map.call(arguments, _convertToDart);
       return _convertToJS(f(...args));
     };
     dart.dsetindex(exports._dartProxies, wrapper, f);
     return wrapper;
   }
   dart.fn(_wrapDartFunction);
   function _convertToDart(o) {
     if (o == null || typeof o == "string" || typeof o == "number" || typeof o == "boolean" || dart.notNull(_isBrowserType(o))) {
       return o;
     } else if (o instanceof Date) {
       let ms = o.getTime();
-      return new core.DateTime.fromMillisecondsSinceEpoch(ms);
+      return new core.DateTime.fromMillisecondsSinceEpoch(dart.asInt(ms));
     } else if (dart.is(o, _DartObject) && dart.jsobject != dart.realRuntimeType(o)) {
       return dart.dload(o, _dartObj);
     } else {
       return _putIfAbsent(exports._dartProxies, o, _wrapToDart);
     }
   }
   dart.fn(_convertToDart, core.Object, [dart.dynamic]);
   function _wrapToDart(o) {
     if (typeof o == "function") {
       return new JsFunction._fromJs(o);
@@ skipping 25 matching lines @@
     let __CastType0 = dart.typedef('__CastType0', () => dart.functionType(dart.dynamic, [E]));
     return __CastType0;
   });
   let __CastType0 = __CastType0$();
   // Exports:
   exports.JsObject = JsObject;
   exports.JsFunction = JsFunction;
   exports.JsArray$ = JsArray$;
   exports.JsArray = JsArray;
 });