dirstate-tree: Extract into a method sorting children of a given node...
dirstate-tree: Extract into a method sorting children of a given node
A later changset will use this in another place.
This is an associated function (that Python would call static method)
instead of a free function so it doesn’t need to be imported separately.
It’s on `Node` rather than `ChildNodes` because the latter is a type alias
to an external type (`HashMap`) so that would require an extension trait
which needs to be imported separately.
Differential Revision:
https://phab.mercurial-scm.org/D10721
