FILES+= SshAskpass.ad
FILESNAME_SshAskpass.ad=SshAskpass-default.ad
instead of
FILES+= SshAskpass-default.ad
because of an obscure bug with "make -j" where it doesn't find
SshAskpass-default.ad in the .PATH correctly, probably because
of the rule created for it from BUILDSYMLINKS by <bsd.files.mk>.
This is not the correct long-term solution, and is a temporary
workaround for PR 24020.