#adb -k unix.0 vmcore.0
*panicstr/s

This will show th panic message, but you might need to work
more than that to actually pinpoint the error down to the
instruction.  Check you the Panic Book.

> #adb -k unix.0 vmcore.0
> *panicstr/s

I prefer to use the crash utility.

  echo status | crash -d vmcore.0 -n unix.0

adb or, on later Solaris releases, mdb

"Panic! Unix system crash dump analysis" by Chris Drake and
Kimberley Brown, published by Prentice Hall, ISBN 0-13-149386-8

"Panic!" has a homepage at http://www.piaffe.org/panic