gas spore explosions while hallucinating (trunk only)
From a bug report: when hallucinating,
messages for affected monsters and/or hero referred to "the gas spore's
explosion" instead of supplying random monster names. This is a little bit
tricky; since it can be displayed multiple times for one explosion, it needs
to be constructed on the fly in explode(). (Caller couldn't have handled
this anyway since it's using the value for killed-by reason which mustn't
be distorted by hallucination.)