Check _localVariableInfo initialized in VariableResolverVisitor.

pkg/analyzer/lib/src/generated/resolver.dart

 // Copyright (c) 2014, 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 analyzer.src.generated.resolver;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 12468 matching lines @@
    * first be visited.  If `null` or unspecified, a new [LibraryScope] will be
    * created based on [definingLibrary] and [typeProvider].
    */
   VariableResolverVisitor(LibraryElement definingLibrary, Source source,
       TypeProvider typeProvider, AnalysisErrorListener errorListener,
       {Scope nameScope})
       : super(definingLibrary, source, typeProvider, errorListener,
             nameScope: nameScope);
 
   @override
+  Object visitBlockFunctionBody(BlockFunctionBody node) {
+    assert(_localVariableInfo != null);
+    return super.visitBlockFunctionBody(node);
+  }
+
+  @override
   Object visitConstructorDeclaration(ConstructorDeclaration node) {
     ExecutableElement outerFunction = _enclosingFunction;
     LocalVariableInfo outerLocalVariableInfo = _localVariableInfo;
     try {
       _localVariableInfo ??= new LocalVariableInfo();
       (node.body as FunctionBodyImpl).localVariableInfo = _localVariableInfo;
       _enclosingFunction = node.element;
       return super.visitConstructorDeclaration(node);
     } finally {
       _localVariableInfo = outerLocalVariableInfo;
       _enclosingFunction = outerFunction;
     }
   }
 
   @override
   Object visitExportDirective(ExportDirective node) => null;
 
   @override
+  Object visitExpressionFunctionBody(ExpressionFunctionBody node) {
+    assert(_localVariableInfo != null);
+    return super.visitExpressionFunctionBody(node);
+  }
+
+  @override
   Object visitFunctionDeclaration(FunctionDeclaration node) {
     ExecutableElement outerFunction = _enclosingFunction;
     LocalVariableInfo outerLocalVariableInfo = _localVariableInfo;
     try {
       _localVariableInfo ??= new LocalVariableInfo();
       (node.functionExpression.body as FunctionBodyImpl).localVariableInfo =
           _localVariableInfo;
       _enclosingFunction = node.element;
       return super.visitFunctionDeclaration(node);
     } finally {
@@ skipping 262 matching lines @@
     nonFields.add(node);
     return null;
   }
 
   @override
   Object visitNode(AstNode node) => node.accept(TypeResolverVisitor_this);
 
   @override
   Object visitWithClause(WithClause node) => null;
 }