Fix various nits in VM patch files.

runtime/lib/string_patch.dart

 // Copyright (c) 2012, 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.
 
 const int _maxAscii = 0x7f;
 const int _maxLatin1 = 0xff;
 const int _maxUtf16 = 0xffff;
 const int _maxUnicode = 0x10ffff;
 
 @patch class String {
@@ skipping 1269 matching lines @@
 
   int codeUnitAt(int index) native "String_codeUnitAt";
 
   bool operator ==(Object other) {
     return super == other;
   }
 }
 
 
 class _StringMatch implements Match {
-  const _StringMatch(int this.start,
-                     String this.input,
-                     String this.pattern);
+  const _StringMatch(this.start, this.input, this.pattern);
 
   int get end => start + pattern.length;
   String operator[](int g) => group(g);
   int get groupCount => 0;
 
   String group(int group) {
     if (group != 0) {
       throw new RangeError.value(group);
     }
     return pattern;
@@ skipping 54 matching lines @@
     int end = index + _pattern.length;
     _current = new _StringMatch(index, _input, _pattern);
     // Empty match, don't start at same location again.
     if (end == _index) end++;
     _index = end;
     return true;
   }
 
   Match get current => _current;
 }