dart2js: Fix getter/setter flags in the model.

dart2js: Fix getter/setter flags in the model.
It was inverting cases 10 and 11.

Here is the relevant part from model.dart:

  /// 00: Does not need any getter.
  /// 01:  function() { return this.field; }
  /// 10:  function(receiver) { return receiver.field; }
  /// 11:  function(receiver) { return this.field; }
  final int getterFlags;

  /// 00: Does not need any setter.
  /// 01:  function(value) { this.field = value; }
  /// 10:  function(receiver, value) { receiver.field = value; }
  /// 11:  function(receiver, value) { this.field = value; }
  final int setterFlags;

R=zarah@google.com

Committed: https://code.google.com/p/dart/source/detail?r=43095

[floitsch, 2015-01-20 22:11:49]

floitsch@google.com changed reviewers:
+ zarah@google.com

[floitsch, 2015-01-22 15:51:56]

floitsch@google.com changed reviewers:
+ herhut@google.com

[floitsch, 2015-01-22 15:51:56]

ping

[zarah, 2015-01-22 19:29:43]

LGTM

[floitsch, 2015-01-23 10:34:03]

Committed patchset #1 (id:1) manually as 43095 (presubmit successful).