### caller() will report line 50.
2  <;> nextstate(main 2 x:50) v
3  <{> enterloop(next->8 last->d redo->4) v
9  <0> pushmark s
a  <#> gv[*X] s/EARLYCV
b  <1> entersub[t2] sKS/TARG,1
c  <|> and(other->4) vK/1
       ### caller() will report line 51
4      <;> nextstate(main 1 x:51) v
5      <0> pushmark s
6      <#> gv[*Y] s/EARLYCV
7      <1> entersub[t4] vKS/TARG,1
8      <0> unstack v
           goto 9
d  <2> leaveloop vK/2
e  <@> leave[1 ref] vKP/REFC