stop passing line numbers into op constructor functions

stop passing line numbers into op constructor functions

Remove the line number parameter from newWHILEOP() and newFOROP()
functions.  Instead, the line number for the impending COP is set by
parser code after constructing the ops.  (In fact the parser was doing
this anyway in most cases.)  This brings newWHILEOP() and newFOROP()
in line with the other op constructors, in that they do not concern
themselves with COPs.