Support `void` as generic argument.

pkg/compiler/lib/src/js_emitter/full_emitter/emitter.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dart2js.js_emitter.full_emitter;
 
 import 'dart:collection' show HashMap;
 import 'dart:convert';
 
 import 'package:js_runtime/shared/embedded_names.dart' as embeddedNames;
@@ skipping 347 matching lines @@
 
       case JsBuiltin.rawRtiToJsConstructorName:
         return jsAst.js.expressionTemplateFor("#.$typeNameProperty");
 
       case JsBuiltin.rawRuntimeType:
         return jsAst.js.expressionTemplateFor("#.constructor");
 
       case JsBuiltin.createFunctionTypeRti:
         return backend.rtiEncoder.templateForCreateFunctionType;
 
+      case JsBuiltin.isVoidRti:
+        return backend.rtiEncoder.templateForIsVoidRti;
+
       case JsBuiltin.isSubtype:
         // TODO(floitsch): move this closer to where is-check properties are
         // built.
         String isPrefix = namer.operatorIsPrefix;
         return jsAst.js
             .expressionTemplateFor("('$isPrefix' + #) in #.prototype");
 
       case JsBuiltin.isGivenTypeRti:
         return jsAst.js.expressionTemplateFor('#.$typeNameProperty === #');
 
@@ skipping 1552 matching lines @@
     // data.
     mapping["_comment"] = "This mapping shows which compiled `.js` files are "
         "needed for a given deferred library import.";
     mapping.addAll(compiler.deferredLoadTask.computeDeferredMap());
     compiler.outputProvider(
         compiler.options.deferredMapUri.path, '', OutputType.info)
       ..add(const JsonEncoder.withIndent("  ").convert(mapping))
       ..close();
   }
 }