Mark analyzer_cli as strong-mode clean

pkg/analyzer_cli/lib/src/options.dart

 // Copyright (c) 2015, 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_cli.src.options;
 
 import 'dart:io';
 
 import 'package:analyzer_cli/src/driver.dart';
 import 'package:args/args.dart';
@@ skipping 148 matching lines @@
   /// Whether to treat lints as fatal
   final bool lintsAreFatal;
 
   /// Initialize options from the given parsed [args].
   CommandLineOptions._fromArgs(
       ArgResults args, Map<String, String> definedVariables)
       : buildAnalysisOutput = args['build-analysis-output'],
         buildMode = args['build-mode'],
         buildModePersistentWorker = args['persistent_worker'],
         buildSummaryFallback = args['build-summary-fallback'],
-        buildSummaryInputs = args['build-summary-input'],
+        buildSummaryInputs = args['build-summary-input'] as List<String>,
         buildSummaryOnly = args['build-summary-only'],
         buildSummaryOnlyAst = args['build-summary-only-ast'],
         buildSummaryOnlyDiet = args['build-summary-only-diet'],
         buildSummaryExcludeInformative =
             args['build-summary-exclude-informative'],
         buildSummaryOutput = args['build-summary-output'],
         buildSummaryOutputSemantic = args['build-summary-output-semantic'],
         buildSuppressExitCode = args['build-suppress-exit-code'],
         dartSdkPath = args['dart-sdk'],
         dartSdkSummaryPath = args['dart-sdk-summary'],
@@ skipping 528 matching lines @@
 
   int _getNextFlagIndex(args, i) {
     for (; i < args.length; ++i) {
       if (args[i].startsWith('--')) {
         return i;
       }
     }
     return i;
   }
 }