add verbose option to show hidden args

pkg/dev_compiler/lib/src/analyzer/context.dart

Index: pkg/dev_compiler/lib/src/analyzer/context.dart
diff --git a/pkg/dev_compiler/lib/src/analyzer/context.dart b/pkg/dev_compiler/lib/src/analyzer/context.dart
index d2bfe96286640100b2269fd74900b4340288ddaf..f30ddc6dc44d2a387ba95e1c8bcfe5c77317daca 100644
--- a/pkg/dev_compiler/lib/src/analyzer/context.dart
+++ b/pkg/dev_compiler/lib/src/analyzer/context.dart
@@ -74,14 +74,14 @@ class AnalyzerOptions {
         declaredVariables: declaredVariables);
   }
 
-  static void addArguments(ArgParser parser) {
+  static void addArguments(ArgParser parser, {bool hide: true}) {
     parser
       ..addOption('summary',
           abbr: 's', help: 'summary file(s) to include', allowMultiple: true)
       ..addOption('dart-sdk',
-          help: 'Dart SDK Path', defaultsTo: null, hide: true)
+          help: 'Dart SDK Path', defaultsTo: null, hide: hide)
       ..addOption('dart-sdk-summary',
-          help: 'Dart SDK Summary Path', defaultsTo: null, hide: true)
+          help: 'Dart SDK Summary Path', defaultsTo: null, hide: hide)
       ..addOption('package-root',
           abbr: 'p', help: 'Package root to resolve "package:" imports')
       ..addOption('url-mapping',