Isolate method ordering in generated JS

[DartBot]

This issue was originally filed by pdr@google.com

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IE9 is sensitive to the method ordering of $inherits(), which needs to be called before methods on a class can be modified.

If the following is compiled:
...
class Background extends Isolate {
  Background() : super() {}
  void main() {
    print('this is background run');
  }
}
...

This JS is generated:
...
function test068070$Background$Dart(){}
function test068070$Background$Dart$isolateFactory(){
  return test068070$Background$Dart.default$factory();
}
test068070$Background$Dart.prototype.getIsolateFactory = function(){
  return test068070$Background$Dart$isolateFactory;
}
;
$inherits(test068070$Background$Dart, Isolate$Dart);
...

In this case, $inherits should be immediately after test068070$Background$Dart.

[DartBot]

This comment was originally written by johnle...@google.com

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r542

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Added Fixed label.