[cfe][InternalNodes] Add InternalRedirectingInitializer

The adds InternalRedirectingInitializer as the node created from the body builder.

This prepare for detaching the internal ArgumentsImpl node from the public Arguments node.

Change-Id: I4f2f8bd267f13bdd4a96feea2c91584c5cb9279f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/465900
Reviewed-by: Chloe Stefantsova <[email protected]>

Author: johnniwinther

pkg/front_end/lib/src/kernel/body_builder_context.dart

@@ -577,7 +577,7 @@ class _SourceClassBodyBuilderDeclarationContext
     ArgumentsImpl arguments, {
     required int fileOffset,
   }) {
-    return new RedirectingInitializer(
+    return new InternalRedirectingInitializer(
       constructorBuilder.invokeTarget as Constructor,
       arguments,
     )..fileOffset = fileOffset;

pkg/front_end/lib/src/kernel/internal_ast.dart

@@ -4967,3 +4967,33 @@ class InternalSuperMethodInvocation extends InternalExpression {
     return "InternalSuperMethodInvocation(${toStringInternal()})";
   }
 }
+
+class InternalRedirectingInitializer extends InternalInitializer {
+  final Constructor target;
+  ArgumentsImpl arguments;
+
+  InternalRedirectingInitializer(this.target, this.arguments) {
+    arguments.parent = this;
+  }
+
+  @override
+  InitializerInferenceResult acceptInference(InferenceVisitorImpl visitor) {
+    return visitor.visitInternalRedirectingInitializer(this);
+  }
+
+  @override
+  // Coverage-ignore(suite): Not run.
+  void toTextInternal(AstPrinter printer) {
+    printer.write('this');
+    if (target.name.text.isNotEmpty) {
+      printer.write('.');
+      printer.write(target.name.text);
+    }
+    printer.writeArguments(arguments, includeTypeArguments: false);
+  }
+
+  @override
+  String toString() {
+    return "InternalRedirectingInitializer(${toStringInternal()})";
+  }
+}

pkg/front_end/lib/src/kernel/resolver.dart

@@ -1234,10 +1234,10 @@ class Resolver {
             );
           }
         }
-      } else if (last is RedirectingInitializer) {
+      } else if (last is InternalRedirectingInitializer) {
         if (bodyBuilderContext.isEnumClass &&
             libraryFeatures.enhancedEnums.isEnabled) {
-          ArgumentsImpl arguments = last.arguments as ArgumentsImpl;
+          ArgumentsImpl arguments = last.arguments;
           List<Expression> enumSyntheticArguments = [
             new VariableGet(function.positionalParameters[0])
               ..parent = last.arguments,

pkg/front_end/lib/src/type_inference/inference_visitor.dart

@@ -12228,8 +12228,15 @@ class InferenceVisitorImpl extends InferenceVisitorBase
   }
 
   @override
+  // Coverage-ignore(suite): Not run.
   InitializerInferenceResult visitRedirectingInitializer(
     RedirectingInitializer node,
+  ) {
+    _unhandledInitializer(node);
+  }
+
+  InitializerInferenceResult visitInternalRedirectingInitializer(
+    InternalRedirectingInitializer node,
   ) {
     ensureMemberType(node.target);
     List<TypeParameter> classTypeParameters =
@@ -12240,7 +12247,7 @@ class InferenceVisitorImpl extends InferenceVisitorBase
           new TypeParameterType.withDefaultNullability(classTypeParameters[i]),
       growable: false,
     );
-    ArgumentsImpl arguments = node.arguments as ArgumentsImpl;
+    ArgumentsImpl arguments = node.arguments;
     // TODO(johnniwinther): Avoid this workaround.
     // The redirecting initializer syntax doesn't include type arguments passed
     // to the target constructor but we need to add them to the arguments before
@@ -12264,7 +12271,8 @@ class InferenceVisitorImpl extends InferenceVisitorBase
     );
     arguments.resetExplicitTypeArguments();
     return new InitializerInferenceResult.fromInvocationInferenceResult(
-      node,
+      new RedirectingInitializer(node.target, arguments)
+        ..fileOffset = node.fileOffset,
       inferenceResult,
     );
   }