If there was no parent, the while loop would try to get the parent of
a `nil`, which crashes and burns.
We now also ignore any non-named parents; this might be unnecessary,
if tree-sitter parent nodes are always named, but I don’t know that at
the moment and it’s not documented very well, so better safe than
sorry.
Change-Id: Ia72ee9241b885ab312f8ecf7a8fbfece7eea8f1b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2263
Reviewed-by: Profpatsch <mail@profpatsch.de>
Tested-by: BuildkiteCI