Add dart analyzer test suite 'analyze_library' that fails if we

sdk/lib/crypto/crypto_utils.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.
 
 part of dart.crypto;
 
 class _LineWrappingStringBuffer {
   _LineWrappingStringBuffer(int this._lineLength) : _sb = new StringBuffer();
 
   void add(String s) {
     if (_lineLength != null && _currentLineLength == _lineLength) {
-      _sb.add('\r\n');
+      _sb.write('\r\n');
       _currentLineLength = 0;
     }
-    _sb.add(s);
+    _sb.write(s);
     _currentLineLength++;
   }
 
   String toString() => _sb.toString();
 
   int _lineLength;
   StringBuffer _sb;
   int _currentLineLength = 0;
 }
 
 abstract class _CryptoUtils {
   static String bytesToHex(List<int> bytes) {
     var result = new StringBuffer();
     for (var part in bytes) {
-      result.add('${part < 16 ? '0' : ''}${part.toRadixString(16)}');
+      result.write('${part < 16 ? '0' : ''}${part.toRadixString(16)}');
     }
     return result.toString();
   }
 
   static String bytesToBase64(List<int> bytes, [int lineLength]) {
     final table =
         const [ 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L',
                 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
                 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
                 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
@@ skipping 26 matching lines @@
       var b1 = bytes[i + 1] & 0xff;
       result.add(table[b0 >> 2]);
       result.add(table[((b0 << 4) | (b1 >> 4)) & 0x3f]);
       result.add(table[(b1 << 2) & 0x3f]);
       result.add('=');
     }
 
     return result.toString();
   }
 }