`double_ended_iterator_last`: note when drop order is changed

`iter.last()` will drop all elements of `iter` in order, while
`iter.next_back()` will drop the non-last elements of `iter` when
`iter` goes out of scope since `.next_back()` does not consume its
argument.

When the transformation proposed by `double_ended_iterator_last` would
concern an iterator whose element type has a significant drop, a note is
added to warn about the possible drop order change, and the suggestion
is switched from `MachineApplicable` to `MaybeIncorrect`.

0 files changed, 0 insertions, 0 deletions