Fixed stack position of return value; ref
When I `#call` the "proc" object created by the `mrb_proc_new_cfunc()` function from Ruby space, the return value did not go into the correct stack position.
This can destroy the calling variable.
This issue is now caused by sorry.
@@ -1515,7 +1515,7 @@ RETRY_TRY_BLOCK:
/* pop stackpos */
ci = cipop(mrb);
pc = ci->pc;
- regs[ci->acc] = recv;
+ regs[ci[1].acc] = recv;
irep = mrb->c->ci->proc->body.irep;
pool = irep->pool;
syms = irep->syms;
