Make the AstFactory API refer to kernel types rather than "shadow" types.

pkg/front_end/lib/src/fasta/builder/ast_factory.dart

 // Copyright (c) 2017, 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.
 
-import 'package:kernel/ast.dart' show DartType, TreeNode;
-
-import 'shadow_ast.dart';
+import 'package:kernel/ast.dart';
 
 /// An abstract class containing factory methods that create AST objects.
 ///
 /// Itended for use by [BodyBuilder] so that it can create either analyzer or
 /// kernel ASTs depending on which concrete factory it is connected to.
 ///
 /// This class is defined in terms of the builder's shadow AST mixins (which are
 /// shared between kernel and analyzer shadow AST representations).
 ///
 /// Note that the analyzer AST representation closely parallels Dart syntax,
@@ skipping 11 matching lines @@
 /// for many AST constructs, not just one.  Note also that for kernel codegen
 /// we want to be very careful not to keep tokens around too long, so consider
 /// having a `toLocation` method on AstFactory that changes tokens to an
 /// abstract type (`int` for kernel, `Token` for analyzer).
 ///
 /// TODO(paulberry): in order to interface with analyzer, we'll need to
 /// shadow-ify [DartType], since analyzer ASTs need to be able to record the
 /// exact tokens that were used to specify a type.
 abstract class AstFactory {
   /// Creates a statement block.
-  ShadowBlock block(List<ShadowStatement> statements, int charOffset);
+  Block block(List<Statement> statements, int charOffset);
 
   /// Creates an integer literal.
-  ShadowIntLiteral intLiteral(value, int charOffset);
+  IntLiteral intLiteral(value, int charOffset);
 
   /// Creates a list literal expression.
   ///
   /// If the list literal did not have an explicitly declared type argument,
   /// [typeArgument] should be `null`.
-  ShadowListLiteral listLiteral(List<ShadowExpression> expressions,
-      DartType typeArgument, bool isConst, int charOffset);
+  ListLiteral listLiteral(List<Expression> expressions, DartType typeArgument,
+      bool isConst, int charOffset);
 
   /// Creates a null literal expression.
-  ShadowNullLiteral nullLiteral(int charOffset);
+  NullLiteral nullLiteral(int charOffset);
 
   /// Creates a return statement.
-  ShadowStatement returnStatement(ShadowExpression expression, int charOffset);
+  Statement returnStatement(Expression expression, int charOffset);
 
   /// Creates a variable declaration statement declaring one variable.
   ///
   /// TODO(paulberry): analyzer makes a distinction between a single variable
   /// declaration and a variable declaration statement (which can contain
   /// multiple variable declarations).  Currently this API only makes sense for
   /// kernel, which desugars each variable declaration to its own statement.
   ///
   /// If the variable declaration did not have an explicitly declared type,
   /// [type] should be `null`.
-  ShadowVariableDeclaration variableDeclaration(String name,
+  VariableDeclaration variableDeclaration(String name,
       {DartType type,
-      ShadowExpression initializer,
+      Expression initializer,
       int charOffset: TreeNode.noOffset,
       bool isFinal: false,
       bool isConst: false});
 }