use == and != to enable handling null/undefined

lib/runtime/dart/isolate.js

 var isolate;
 (function(exports) {
   'use strict';
   class Capability extends core.Object {
     Capability() {
       return new _isolate_helper.CapabilityImpl();
     }
   }
   class IsolateSpawnException extends core.Object {
     IsolateSpawnException(message) {
@@ skipping 22 matching lines @@
         return dart.as(_isolate_helper.IsolateNatives.spawnFunction(entryPoint, message, paused).then(dart.closureWrap((msg) => new Isolate(dart.as(dart.dindex(msg, 1), SendPort), {pauseCapability: dart.as(dart.dindex(msg, 2), Capability), terminateCapability: dart.as(dart.dindex(msg, 3), Capability)}), "(List<dynamic>) → dynamic")), async.Future$(Isolate));
       } catch (e) {
         let st = dart.stackTrace(e);
         return new async.Future.error(e, st);
       }
 
     }
     static spawnUri(uri, args, message, opts) {
       let paused = opts && 'paused' in opts ? opts.paused : false;
       let packageRoot = opts && 'packageRoot' in opts ? opts.packageRoot : null;
-      if (packageRoot !== null)
+      if (packageRoot != null)
         throw new core.UnimplementedError("packageRoot");
       try {
         if (dart.is(args, core.List$(core.String))) {
           for (let i = 0; dart.notNull(i) < dart.notNull(args.length); i = dart.notNull(i) + 1) {
             if (!(typeof args.get(i) == 'string')) {
               throw new core.ArgumentError(`Args must be a list of Strings ${args}`);
             }
           }
-        } else if (args !== null) {
+        } else if (args != null) {
           throw new core.ArgumentError(`Args must be a list of Strings ${args}`);
         }
         return dart.as(_isolate_helper.IsolateNatives.spawnUri(uri, args, message, paused).then(dart.closureWrap((msg) => new Isolate(dart.as(dart.dindex(msg, 1), SendPort), {pauseCapability: dart.as(dart.dindex(msg, 2), Capability), terminateCapability: dart.as(dart.dindex(msg, 3), Capability)}), "(List<dynamic>) → dynamic")), async.Future$(Isolate));
       } catch (e) {
         let st = dart.stackTrace(e);
         return new async.Future.error(e, st);
       }
 
     }
     pause(resumeCapability) {
       if (resumeCapability === void 0)
         resumeCapability = null;
-      if (resumeCapability === null)
+      if (resumeCapability == null)
         resumeCapability = new Capability();
       this[_pause](resumeCapability);
       return resumeCapability;
     }
     [_pause](resumeCapability) {
       let message = new core.List(3);
       dart.dsetindex(message, 0, "pause");
       dart.dsetindex(message, 1, this.pauseCapability);
       dart.dsetindex(message, 2, resumeCapability);
       this.controlPort.send(message);
@@ skipping 127 matching lines @@
   }
   // Exports:
   exports.Capability = Capability;
   exports.IsolateSpawnException = IsolateSpawnException;
   exports.Isolate = Isolate;
   exports.SendPort = SendPort;
   exports.ReceivePort = ReceivePort;
   exports.RawReceivePort = RawReceivePort;
   exports.RemoteError = RemoteError;
 })(isolate || (isolate = {}));