Concerning 49d1dbaa (remove comment about OPpTARGET_MY)

It was for the sake of OPpTARGET_MY that the mask was added
(in b162f9ead0).  Previously, MAXARG was #defined simply as
PL_op->op_private.

Now that regen/opcode.pl checks that OPpARG4_MASK and OPpTARGET_MY do
not conflict, the comment is indeed unnecessary.  (So things can stay
as they are.)

I thought this might be informative, or at least interesting.

• Concerning 49d1dbaa (remove comment about OPpTARGET_MY) by Father Chrysostomos