Bird 2.0.0 -- unknown filter instructions

[Luis Ressel]

Hello *,

I've been experimenting with bird 2.0.0 for a few days now. Apart from
the memory leak (which Ondrej's patch appears to fix), the most serious
issue I've run into is a spurious bird crash caused by the filter code.
Twice so far, bird died when I ran 'birdc configure', with the messages
"<BUG> Unknown instruction 26912" and "<BUG> Unknown instruction 0",
respectively.

I haven't been able to reliably reproduce these crashes, though. If
someone has an idea how to do this, or at least how to narrow down
which part of my lengthy filter config is causing it, that'd be much
appreciated!

Regards,
Luis Ressel