Modifications (Ian Hayes)

const.c:	17jul79	use 16bit value only if an integer
proc.c:	17jul79	pack generated code is wrong re width of item
rval.c:	17jul80	opname left out of comparison of pointers error message
nl.c:	15apr80	intset was not truely defined
clas.c:	3sep80	classify of the empty set caused panic as of type TSET
0.h:	3sep80	remove definition of DEBUG for smaller compiler
