Fix derived PartialOrd operators
The derived implementation of `partial_cmp` compares matching fields one
by one, stopping the computation when the result of a comparison is not
equal to `Some(Equal)`.
On the other hand the derived implementation for `lt`, `le`, `gt` and
`ge` continues the computation when the result of a field comparison is
`None`, consequently those operators are not transitive and inconsistent
with `partial_cmp`.
Fix the inconsistency by using the default implementation that fall-backs
to the `partial_cmp`. This also avoids creating very deeply nested
closures that were quite costly to compile.
Fixes#81373.
Helps with #81278, #80118.
c648bd5558