Remove old #import, #source, and #library syntax from tests/standalone.

tests/standalone/io/fuzz_support.dart

Index: tests/standalone/io/fuzz_support.dart
diff --git a/tests/standalone/io/fuzz_support.dart b/tests/standalone/io/fuzz_support.dart
index 9cd384fd427118ed29838257e9dc74e79a5de332..64f96a75b5ddcb8f94555d0263f24a7c7ae6228f 100644
--- a/tests/standalone/io/fuzz_support.dart
+++ b/tests/standalone/io/fuzz_support.dart
@@ -2,9 +2,9 @@
 // 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('fuzz_support');
+library fuzz_support;
 
-#import('dart:io');
+import "dart:io";
 
 const typeMapping = const {
   'null': null,