cannot use default parameters in __export__ed class definition

[kazuho]

The following code should be able to compile (since it is just defining a default parameter value), but fails with the error below.

abstract __export__ class T {
  abstract function f(b : boolean = false) : void;
}

[tmp/export-default-param.jsx:2:11] methods with __export__ attribute cannot be overloaded
  abstract function f(b : boolean = false) : void;
           ^^^^^^^^

[tmp/export-default-param.jsx:2:11] Note: previously defined here
  abstract function f(b : boolean = false) : void;
           ^^^^^^^^