Add support for parsing #void with Fasta.

pkg/front_end/lib/src/fasta/kernel/body_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.body_builder;
 
 import '../parser/parser.dart' show FormalParameterType, optional;
 
 import '../parser/error_kind.dart' show ErrorKind;
 
@@ skipping 2217 matching lines @@
       return internalError("Unhandled: ${builder.runtimeType}");
     }
   }
 
   @override
   void handleOperator(Token token) {
     debugEvent("Operator");
     push(new Operator(token.stringValue)..fileOffset = token.charOffset);
   }
 
+  @override
+  void handleSymbolVoid(Token token) {
+    logEvent("SymbolVoid");
+  }
+
   dynamic addCompileTimeError(int charOffset, String message) {
     return library.addCompileTimeError(charOffset, message, uri);
   }
 
   @override
   void handleInvalidFunctionBody(Token token) {
     if (member.isNative) {
       push(NullValue.FunctionBody);
     } else {
       push(new Block(<Statement>[new InvalidStatement()]));
@@ skipping 434 matching lines @@
   } else if (node is TypeDeclarationBuilder) {
     return node.name;
   } else if (node is PrefixBuilder) {
     return node.name;
   } else if (node is ThisPropertyAccessor) {
     return node.name.name;
   } else {
     return internalError("Unhandled: ${node.runtimeType}");
   }
 }