Issue #1786: Revise existing test which was completely inadequate.
Fix #1786 by maintaining state on the expression transformer so we can distingush the normal spread case from the recursive method reference spread case, and changing the code we generate in the method reference case.

We also need to stop assuming the saved-evaluated-primary is called
$instance$, because for spread method refs it no longer is.
Trivial changes to do with managing state on the ExpressionTransformer.
Minor.
Fix #1811
Issue #1811: Bulk update changed .src.
Issue #1811: Enable test.