Implement doWhilst via whilst

[megawac]

No description provided.

[aearly]

Hmnn, this means that the second and later invocations of the test in whilst will be called with the callback arguments -- might lead to subtle breaking changes. I'm sure most people are passing a function expression with no parameters, but some people might be passing a variadic method somehow.

[megawac]

I mean, if people don't expect parameters they won't be handling them. I would be extremely surprised if this broke anyones code (plus its a nice little enhancement to whilst (same goes for during in the other pr)

[aearly]

Okay, I guess we'll try it and see...