Remove requiredTypes

pkg/compiler/lib/src/js_backend/backend_impact.dart

 // Copyright (c) 2015, 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_helpers.impact;
 
 import '../common/names.dart' show
     Identifiers;
 import '../compiler.dart' show
     Compiler;
@@ skipping 133 matching lines @@
         find(JavaScriptMapConstant.DART_CLASS),
         find(JavaScriptMapConstant.DART_PROTO_CLASS),
         find(JavaScriptMapConstant.DART_STRING_CLASS),
         find(JavaScriptMapConstant.DART_GENERAL_CLASS)]);
   }
 
   BackendImpact get symbolConstructor => new BackendImpact(
       staticUses: [
         helpers.compiler.symbolValidatedConstructor]);
 
+  BackendImpact get constSymbol => new BackendImpact(
+      instantiatedClasses: [
+        compiler.symbolClass],
+      staticUses: [
+        compiler.symbolConstructor.declaration]);
 
   BackendImpact get incDecOperation =>
       needsInt('Needed for the `+ 1` or `- 1` operation of ++/--.');
 
   /// Helper for registering that `int` is needed.
   BackendImpact needsInt(String reason) {
     // TODO(johnniwinther): Register [reason] for use in dump-info.
     return new BackendImpact(
         instantiatedClasses: [helpers.compiler.intClass]);
   }
@@ skipping 49 matching lines @@
       staticUses: [
         helpers.cyclicThrowHelper]);
 
   BackendImpact get typeLiteral => new BackendImpact(
       instantiatedClasses: [
         backend.typeImplementation],
       staticUses: [
         helpers.createRuntimeType]);
 
   BackendImpact get stackTraceInCatch => new BackendImpact(
+      instantiatedClasses: [
+        helpers.compiler.stackTraceClass],
       staticUses: [
         helpers.traceFromException]);
 
   BackendImpact get syncForIn => new BackendImpact(
       // The SSA builder recognizes certain for-in loops and can generate calls
       // to throwConcurrentModificationError.
       staticUses: [
         helpers.checkConcurrentModificationError]);
 
   BackendImpact get typeVariableExpression => new BackendImpact(
@@ skipping 46 matching lines @@
   BackendImpact get functionTypeCheck => new BackendImpact(
       staticUses: [
         helpers.functionTypeTestMetaHelper]);
 
   BackendImpact get nativeTypeCheck => new BackendImpact(
       staticUses: [
         // We will neeed to add the "$is" and "$as" properties on the
         // JavaScript object prototype, so we make sure
         // [:defineProperty:] is compiled.
         helpers.defineProperty]);
+
+  BackendImpact get closure => new BackendImpact(
+      instantiatedClasses: [
+        helpers.compiler.functionClass]);
 }