Stack adjustment should be based on `p->upper`; fix
It used to be based on `ci->proc` but the callinfo position may be
wrong when `ecall()` is called during stack rewinding from `OP_RETURN`.
@@ -309,7 +309,6 @@ static void
ecall(mrb_state *mrb)
{
struct RProc *p;
- int nregs;
struct mrb_context *c = mrb->c;
mrb_callinfo *ci = c->ci;
struct RObject *exc;
@@ -325,7 +324,6 @@ ecall(mrb_state *mrb)
p = c->ensure[i];
if (!p) return;
mrb_assert(!MRB_PROC_CFUNC_P(p));
- nregs = ci->proc->body.irep->nregs;
c->ensure[i] = NULL;
cioff = ci - c->cibase;
ci = cipush(mrb);
@@ -338,7 +336,7 @@ ecall(mrb_state *mrb)
ci->target_class = MRB_PROC_TARGET_CLASS(p);
env = MRB_PROC_ENV(p);
mrb_assert(env);
- c->stack += nregs;
+ c->stack += p->upper->body.irep->nregs;
exc = mrb->exc; mrb->exc = 0;
if (exc) {
mrb_gc_protect(mrb, mrb_obj_value(exc));
