feat(nix/readTree): record list of children added by readTree r/2869

This change adds a new attribute to readTree nodes, `__readTreeChildren`
which is a list of attribute names added to this node by readTree.

This is then used by `gather` for `ci.targets` to avoid evaluating
attributes unnecessarily. Especially since Nix is not as lazy as we'd
like when determining types (i. e. child ? __readTree needs to force
`child` even when it's not an attribute set), evaluating attributes
unnecessarily is sometimes problematic.

Change-Id: I0a98691d41f987e23ee7e9ba21fbe465da5fe402

0 files changed, 0 insertions, 0 deletions