hal: make 'save comp' order match original 'loadrt' order

.. by changing hal_init to insert at the end of the list.  This is a
little clunky, because we don't have "insert at list end" as a primitive,
but it felt like the better choice than doing backwards iteration in
'save comp', which in a naive implementation has a runtime complexity
of O(n^2) due to the single-linked nature of the list.
tests: save.0: use expected result as hal script too

.. this makes is all the more certain that halcmd save is doing
the right thing, since it doesn't allow it to introduce any differences.