Add close to input stream and cleanup socket and streams

tests/standalone/src/ReadIntoConstList.dart

 // Copyright (c) 2011, 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.
 
 // Regression test for missing immutability check in the ListSet
 // methods in the API. This allowed overwriting const Lists.
 
 String getFilename(String path) =>
     new File(path).existsSync() ? path : 'runtime/' + path;
 
 void main() {
   var a = const [0];
   var b = const [0];
   Expect.isTrue(a === b);
 
   String filename = getFilename("bin/file_test.cc");
   File file = new File(filename);
-  FileInputStream input = file.openInputStream();
+  InputStream input = file.openInputStream();
   try {
     input.readInto(a, 0, 1);
     Expect.fail("no exception thrown");
   } catch (var e) {
     Expect.isTrue(e is FileIOException);
   }
   Expect.equals(0, a[0]);
   Expect.equals(0, b[0]);
 }