Fix deprecated StringBuffer usages in Intl

pkg/intl/lib/number_format.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.
 
 library number_format;
 
 import 'dart:math';
 
 import "intl.dart";
 import "number_symbols.dart";
@@ skipping 148 matching lines @@
     var intValue = number.truncate().toInt();
     var multiplied = (number * power).round();
     var fracValue = (multiplied - intValue * power).floor().toInt();
     var fractionPresent = _minimumFractionDigits > 0 || fracValue > 0;
 
     // On dartj2s the integer part may be large enough to be a floating
     // point value, in which case we reduce it until it is small enough
     // to be printed as an integer and pad the remainder with zeros.
     var paddingDigits = new StringBuffer();
     while ((intValue & 0x7fffffff) != intValue) {
-      paddingDigits.add(symbols.ZERO_DIGIT);
+      paddingDigits.write(symbols.ZERO_DIGIT);
       intValue = intValue ~/ 10;
     }
     var integerDigits = "${intValue}${paddingDigits}".codeUnits;
     var digitLength = integerDigits.length;
 
     if (_hasPrintableIntegerPart(intValue)) {
       _pad(_minimumIntegerDigits - digitLength);
       for (var i = 0; i < digitLength; i++) {
         _addDigit(integerDigits[i]);
         _group(digitLength, i);
@@ skipping 40 matching lines @@
 
   /**
    * Create a new empty buffer. See comment on [_buffer] variable for why
    * we have it as an instance variable rather than passing it on the stack.
    */
   void _newBuffer() { _buffer = new StringBuffer(); }
 
   /** A group of methods that provide support for writing digits and other
    * required characters into [_buffer] easily.
    */
-  void _add(String x) { _buffer.add(x);}
-  void _addCharCode(int x) { _buffer.addCharCode(x); }
-  void _addZero() { _buffer.add(symbols.ZERO_DIGIT); }
-  void _addDigit(int x) { _buffer.addCharCode(_localeZero + x - _zero); }
+  void _add(String x) { _buffer.write(x);}
+  void _addCharCode(int x) { _buffer.writeCharCode(x); }
+  void _addZero() { _buffer.write(symbols.ZERO_DIGIT); }
+  void _addDigit(int x) { _buffer.writeCharCode(_localeZero + x - _zero); }
 
   /** Print padding up to [numberOfDigits] above what's included in [basic]. */
   void _pad(int numberOfDigits, [String basic = '']) {
     for (var i = 0; i < numberOfDigits - basic.length; i++) {
       _add(symbols.ZERO_DIGIT);
     }
     for (var x in basic.codeUnits) {
       _addDigit(x);
     }
   }
@@ skipping 32 matching lines @@
   }
 
   /**
    * Returns the suffix for [x] based on wether it's positive or negative.
    * In en_US there are no suffixes for positive or negative.
    */
   String _signSuffix(num x) {
     return x.isNegative ? _negativeSuffix : _positiveSuffix;
   }
 }