Support multiple resolution inputs from command line.

tests/compiler/dart2js/serialization/duplicate_library_test.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 dart2js.serialization.duplicate_libraryc_test;
+
+import 'dart:async';
+import 'package:async_helper/async_helper.dart';
+import 'package:expect/expect.dart';
+import 'package:compiler/src/commandline_options.dart';
+import 'package:compiler/src/common/names.dart';
+import 'package:compiler/src/compiler.dart';
+import 'package:compiler/src/filenames.dart';
+import '../memory_compiler.dart';
+import 'helper.dart';
+import 'test_data.dart';
+
+void main(List<String> args) {
+  asyncTest(() async {
+    SerializedData data = await serializeDartCore(
+        arguments: new Arguments.from(args));
+    Map<String, String> sourceFiles = data.toMemorySourceFiles();
+    List<Uri> resolutionInputs = data.toUris();
+    Uri extraUri = Uri.parse('memory:extraUri');
+    sourceFiles[extraUri.path] = data.data;
+    resolutionInputs.add(extraUri);
+
+    DiagnosticCollector collector = new DiagnosticCollector();
+    await runCompiler(
+        entryPoint: Uris.dart_core,
+        memorySourceFiles: sourceFiles,
+        resolutionInputs: resolutionInputs,
+        diagnosticHandler: collector,
+        options: [Flags.analyzeAll]);
+    Expect.isTrue(collector.errors.isNotEmpty,
+        "Expected duplicate serialized library errors.");
+  });
+}