Fix for parsing EmptyFunctionBody with Fasta.

pkg/front_end/lib/src/fasta/analyzer/ast_builder.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 fasta.analyzer.ast_builder;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/dart/ast/ast_factory.dart' show AstFactory;
 import 'package:analyzer/dart/ast/standard_ast_factory.dart' as standard;
 import 'package:analyzer/dart/ast/token.dart' as analyzer show Token;
@@ skipping 215 matching lines @@
     }
   }
 
   void doPropertyGet(Token token) {}
 
   void endExpressionStatement(Token token) {
     debugEvent("ExpressionStatement");
     push(ast.expressionStatement(pop(), toAnalyzerToken(token)));
   }
 
+  @override
+  void endEmptyFunctionBody(Token semicolon) {
+    debugEvent("EmptyFunctionBody");
+    // TODO(scheglov) Change the parser to not produce these modifiers.
+    pop(); // star
+    pop(); // async
+    push(ast.emptyFunctionBody(toAnalyzerToken(semicolon)));
+  }
+
   void endFunctionBody(int count, Token beginToken, Token endToken) {
     debugEvent("FunctionBody");
     List statements = popList(count);
     if (beginToken != null) {
       exitLocalScope();
     }
     Block block = ast.block(
         toAnalyzerToken(beginToken), statements, toAnalyzerToken(endToken));
     analyzer.Token star = pop();
     analyzer.Token asyncKeyword = pop();
     push(ast.blockFunctionBody(asyncKeyword, star, block));
   }
 
   void finishFunction(formals, asyncModifier, FunctionBody body) {
     debugEvent("finishFunction");
     Statement bodyStatement;
-    if (body is ExpressionFunctionBody) {
+    if (body is EmptyFunctionBody) {
+      bodyStatement = ast.emptyStatement(body.semicolon);
+    } else if (body is ExpressionFunctionBody) {
       bodyStatement = ast.returnStatement(null, body.expression, null);
     } else {
       bodyStatement = (body as BlockFunctionBody).block;
     }
     var kernel = toKernel(bodyStatement, elementStore, library.library, scope);
     if (member is ProcedureBuilder) {
       ProcedureBuilder builder = member;
       builder.body = kernel;
     } else {
       internalError("Internal error: expected procedure, but got: $member");
@@ skipping 1312 matching lines @@
       } else if (identical('static', s)) {
         staticKeyword = token;
       } else if (identical('var', s)) {
         finalConstOrVarKeyword = token;
       } else {
         internalError('Unhandled modifier: $s');
       }
     }
   }
 }