Hello,

This patch just fills in a gap in the current *_REGNUMs by adding 
PS_REGNUM.  Unlike the others.  This one really does allow -1 as the 
default value.

(FP_REGNUM et.al. require real values as there is code around that, 
unfortunatly, depends on there being a real FP register et.al.  ulgh).

committed,
Andrew