added bool type to named args in lib/io and lib/_internal

sdk/lib/io/file_system_entity.dart

Index: sdk/lib/io/file_system_entity.dart
diff --git a/sdk/lib/io/file_system_entity.dart b/sdk/lib/io/file_system_entity.dart
index b492171c66e068db832163e5b051ceb07bef25d6..fdeb923c6de41dc31715e1dc13192afcd6546ee2 100644
--- a/sdk/lib/io/file_system_entity.dart
+++ b/sdk/lib/io/file_system_entity.dart
@@ -316,7 +316,7 @@ abstract class FileSystemEntity {
    * [FileSystemEntity] when the deletion is done. If the [FileSystemEntity]
    * cannot be deleted, the future completes with an exception.
    */
-  Future<FileSystemEntity> delete({recursive: false})
+  Future<FileSystemEntity> delete({bool recursive: false})
       => _delete(recursive: recursive);
 
   /**
@@ -335,7 +335,7 @@ abstract class FileSystemEntity {
    *
    * Throws an exception if the [FileSystemEntity] cannot be deleted.
    */
-  void deleteSync({recursive: false})
+  void deleteSync({bool recursive: false})
       => _deleteSync(recursive: recursive);
 
 
@@ -365,8 +365,8 @@ abstract class FileSystemEntity {
                                events,
                                recursive).stream;
 
-  Future<FileSystemEntity> _delete({recursive: false});
-  void _deleteSync({recursive: false});
+  Future<FileSystemEntity> _delete({bool recursive: false});
+  void _deleteSync({bool recursive: false});
 
   /**
    * Checks whether two paths refer to the same object in the