dart2js: Pass type information to constructor rather than add later.

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

Index: pkg/compiler/lib/src/js_backend/constant_emitter.dart
diff --git a/pkg/compiler/lib/src/js_backend/constant_emitter.dart b/pkg/compiler/lib/src/js_backend/constant_emitter.dart
index 391a35c269e05bd3975edb96c0924206cd9cf34d..d21083f6624610bc266520fc5c57a194369d3138 100644
--- a/pkg/compiler/lib/src/js_backend/constant_emitter.dart
+++ b/pkg/compiler/lib/src/js_backend/constant_emitter.dart
@@ -254,6 +254,7 @@ class ConstantEmitter implements ConstantValueVisitor<jsAst.Expression, Null> {
     jsAst.Expression constructor =
         backend.emitter.constructorAccess(classElement);
     jsAst.Expression value = new jsAst.New(constructor, arguments);
+    // Fix. Add an argument.

[Siggi Cherem (dart-lang), 2016/08/19 16:39:46]

did you indent to fix this one with this CL too?

     return maybeAddTypeArguments(constant.type, value);
   }
 
@@ -307,8 +308,11 @@ class ConstantEmitter implements ConstantValueVisitor<jsAst.Expression, Null> {
     element.forEachInstanceField((_, FieldElement field) {
       fields.add(constantReferenceGenerator(constant.fields[field]));
     }, includeSuperAndInjectedMembers: true);
+    if (backend.classNeedsRti(constant.type.element)) {
+      fields.add(_reifiedTypeArguments(constant.type));
+    }
     jsAst.New instantiation = new jsAst.New(constructor, fields);
-    return maybeAddTypeArguments(constant.type, instantiation);
+    return instantiation;
   }
 
   String stripComments(String rawJavaScript) {
@@ -320,20 +324,23 @@ class ConstantEmitter implements ConstantValueVisitor<jsAst.Expression, Null> {
     if (type is InterfaceType &&
         !type.treatAsRaw &&
         backend.classNeedsRti(type.element)) {
-      InterfaceType interface = type;
-      RuntimeTypesEncoder rtiEncoder = backend.rtiEncoder;
-      Iterable<jsAst.Expression> arguments = interface.typeArguments.map(
-          (DartType type) =>
-              rtiEncoder.getTypeRepresentationWithPlaceholders(type, (_) {}));
-      jsAst.Expression argumentList =
-          new jsAst.ArrayInitializer(arguments.toList());
       return new jsAst.Call(
           getHelperProperty(backend.helpers.setRuntimeTypeInfo),
-          [value, argumentList]);
+          [value, _reifiedTypeArguments(type)]);
     }
     return value;
   }
 
+  jsAst.Expression _reifiedTypeArguments(InterfaceType type) {
+    RuntimeTypesEncoder rtiEncoder = backend.rtiEncoder;
+    Iterable<jsAst.Expression> arguments = type.typeArguments.map(
+        (DartType type) =>
+        rtiEncoder.getTypeRepresentationWithPlaceholders(type, (_) {}));
+    jsAst.Expression argumentList =
+        new jsAst.ArrayInitializer(arguments.toList());
+    return argumentList;
+  }
+
   @override
   jsAst.Expression visitDeferred(DeferredConstantValue constant, [_]) {
     return constantReferenceGenerator(constant.referenced);