Switch ddc to use @JS instead of @JSName

lib/runtime/dart/js.js

 dart_library.library('dart/js', null, /* Imports */[
   "dart/_runtime",
   '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 372 matching lines @@
   });
   function _putIfAbsent(weakMap, o, getValue) {
     let value = weakMap.get(o);
     if (value == null) {
       value = dart.dcall(getValue, o);
       weakMap.set(o, value);
     }
     return value;
   }
   dart.fn(_putIfAbsent, core.Object, [dart.dynamic, dart.dynamic, dart.functionType(dart.dynamic, [dart.dynamic])]);
+  function allowInterop(f) {
+    return f;
+  }
+  dart.fn(allowInterop, core.Function, [core.Function]);
+  dart.defineLazyProperties(exports, {
+    get _interopCaptureThisExpando() {
+      return new (core.Expando$(core.Function))();
+    },
+    set _interopCaptureThisExpando(_) {}
+  });
+  function allowInteropCaptureThis(f) {
+    let ret = exports._interopCaptureThisExpando.get(f);
+    if (ret == null) {
+      ret = dart.as(function() {
+        let args = [this];
+        for (let arg of arguments) {
+          args.push(arg);
+        }
+        return f(...args);
+      }, core.Function);
+      exports._interopCaptureThisExpando.set(f, ret);
+    }
+    return ret;
+  }
+  dart.fn(allowInteropCaptureThis, core.Function, [core.Function]);
   let __CastType0$ = dart.generic(function(E) {
     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;
+  exports.allowInterop = allowInterop;
+  exports.allowInteropCaptureThis = allowInteropCaptureThis;
 });