As itersave points to the initial CxITERVAR(), and the state of

As itersave points to the initial CxITERVAR(), and the state of
SvPADMY() does not change over the duration of the scope, we can
perform conditional actions at loop push time. For the non-pad case,
a reference to the initial CxITERVAR() is already held on the scope
stack thanks to SAVEGENERICSV(*svp); in pp_enteriter. So there is no
need to save another reference to it in itersave - it's not going away.

p4raw-id: //depot/perl@33076