Clear ensure stack after calling in `OP_EPOP`; 3856
@@ -1338,6 +1338,7 @@ RETRY_TRY_BLOCK:
pc = pc + 1;
for (n=0; n<a; n++) {
proc = mrb->c->ensure[epos+n];
+ mrb->c->ensure[epos+n] = NULL;
irep = proc->body.irep;
ci = cipush(mrb);
ci->mid = ci[-1].mid;
