Remove BlockExpression from the Kernel language.

lib/visitor.dart

 // Copyright (c) 2016, 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 kernel.ast.visitor;
 
 import 'ast.dart';
 
 abstract class ExpressionVisitor<R> {
   R defaultExpression(Expression node) => null;
   R defaultBasicLiteral(BasicLiteral node) => defaultExpression(node);
@@ skipping 33 matching lines @@
   R visitListLiteral(ListLiteral node) => defaultExpression(node);
   R visitMapLiteral(MapLiteral node) => defaultExpression(node);
   R visitAwaitExpression(AwaitExpression node) => defaultExpression(node);
   R visitFunctionExpression(FunctionExpression node) => defaultExpression(node);
   R visitStringLiteral(StringLiteral node) => defaultBasicLiteral(node);
   R visitIntLiteral(IntLiteral node) => defaultBasicLiteral(node);
   R visitDoubleLiteral(DoubleLiteral node) => defaultBasicLiteral(node);
   R visitBoolLiteral(BoolLiteral node) => defaultBasicLiteral(node);
   R visitNullLiteral(NullLiteral node) => defaultBasicLiteral(node);
   R visitLet(Let node) => defaultExpression(node);
-  R visitBlockExpression(BlockExpression node) => defaultExpression(node);
 }
 
 abstract class StatementVisitor<R> {
   R defaultStatement(Statement node) => null;
 
   R visitInvalidStatement(InvalidStatement node) => defaultStatement(node);
   R visitExpressionStatement(ExpressionStatement node) =>
       defaultStatement(node);
   R visitBlock(Block node) => defaultStatement(node);
   R visitEmptyStatement(EmptyStatement node) => defaultStatement(node);
@@ skipping 84 matching lines @@
   R visitListLiteral(ListLiteral node) => defaultExpression(node);
   R visitMapLiteral(MapLiteral node) => defaultExpression(node);
   R visitAwaitExpression(AwaitExpression node) => defaultExpression(node);
   R visitFunctionExpression(FunctionExpression node) => defaultExpression(node);
   R visitStringLiteral(StringLiteral node) => defaultBasicLiteral(node);
   R visitIntLiteral(IntLiteral node) => defaultBasicLiteral(node);
   R visitDoubleLiteral(DoubleLiteral node) => defaultBasicLiteral(node);
   R visitBoolLiteral(BoolLiteral node) => defaultBasicLiteral(node);
   R visitNullLiteral(NullLiteral node) => defaultBasicLiteral(node);
   R visitLet(Let node) => defaultExpression(node);
-  R visitBlockExpression(BlockExpression node) => defaultExpression(node);
 
   // Statements
   R defaultStatement(Statement node) => defaultTreeNode(node);
   R visitInvalidStatement(InvalidStatement node) => defaultStatement(node);
   R visitExpressionStatement(ExpressionStatement node) =>
       defaultStatement(node);
   R visitBlock(Block node) => defaultStatement(node);
   R visitEmptyStatement(EmptyStatement node) => defaultStatement(node);
   R visitAssertStatement(AssertStatement node) => defaultStatement(node);
   R visitLabeledStatement(LabeledStatement node) => defaultStatement(node);
@@ skipping 137 matching lines @@
   /// By default, recursion stops at this point.
   DartType visitDartType(DartType node) => node;
 
   Supertype visitSupertype(Supertype node) => node;
 
   TreeNode defaultTreeNode(TreeNode node) {
     node.transformChildren(this);
     return node;
   }
 }