internal/core/adt: rename node to vertex
This allows introducing a node method, needed to
satisfy an upcoming interface.
Signed-off-by: Marcel van Lohuizen <mpvl@gmail.com>
Change-Id: I5b51752218882bb1d4a7d1edc06196268f130535
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1167911
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: CUEcueckoo <cueckoo@cuelang.org>
Unity-Result: CUE porcuepine <cue.porcuepine@gmail.com>