Handle 'part of' declarations with URI correctly in Fasta.

pkg/analyzer/lib/src/summary/fasta/summary_builder.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.
 
 /// Logic to build unlinked summaries.
 library summary.src.summary_builder;
 
 import 'package:front_end/src/fasta/parser/class_member_parser.dart';
 import 'package:front_end/src/fasta/parser/identifier_context.dart';
 import 'package:front_end/src/fasta/parser/parser.dart';
@@ skipping 1301 matching lines @@
   void endPart(Token partKeyword, Token semicolon) {
     debugEvent("Part");
     String uri = pop();
     // ignore: strong_mode_down_cast_composite
     List<UnlinkedExpr> metadata = pop();
     topScope.unit.parts.add(new UnlinkedPartBuilder(annotations: metadata));
     topScope.publicNamespace.parts.add(uri);
     checkEmpty();
   }
 
-  void endPartOf(Token partKeyword, Token semicolon) {
+  void endPartOf(Token partKeyword, Token semicolon, bool hasName) {
     debugEvent("endPartOf");
     String name = pop();
     pop(); // metadata
     topScope.unit.isPartOf = true;
     if (name == 'dart.core') isCoreLibrary = true;
   }
 
   void endRedirectingFactoryBody(Token beginToken, Token endToken) {
     debugEvent("RedirectingFactoryBody");
     pop(); // Discard ConstructorReferenceBuilder.
@@ skipping 257 matching lines @@
 }
 
 /// Internal representation of an initialized name.
 class _InitializedName {
   final String name;
   final UnlinkedExecutableBuilder initializer;
   _InitializedName(this.name, this.initializer);
 
   toString() => "II:" + (initializer != null ? "$name = $initializer" : name);
 }