* Merge in HPPA/BSD patches from Utah:
* defs.h: Add const to 2nd arg of psignal prototype.
* hppah-tdep.c: Renamed to hppa-tdep.c 'cuz it's common code with
BSD now.
* hppab-core.c: Deleted. No longer useful.
* hppab-nat.c: #include more files. Use PT_WUREGS, not
PT_WRITE_U.
* hppab-tdep.c: Deleted. Supplanted by hppa-tdep.c.
* config/pa/hppabsd.mh (NATDEPFILES): Remove hppab-core.o.
* config/pa/hppabsd.mt (TDEPFILES): hppab-tdep.o => hppa-tdep.o
* config/pa/hppahpux.mt (TDEPFILES): hppab-tdep.o => hppa-tdep.o
* config/pa/xm-hppab.h: #define SET_STACK_LIMIT_HUGE.