Ptx is one of those rare (unique?) machines that doesn't  have an indirect 
branch.  optabs  is prepared for such  a target and emits a sorry when an 
indirect branch is needed.  However it then goes on to try and  emit such an 
instruction and ends up ICEing.

Fixed thusly, ok?  (Or is the right solution to define a dummy indirect branch 
in the PTX  md file?)

nathan