Merge pull request #5307 from dearblue/stackerr

Raise SystemStackError if mruby VM stack expansion fails

src/vm.c

@@ -197,7 +197,7 @@ stack_extend_alloc(mrb_state *mrb, mrb_int room)
     size += room;
 #endif
 
-  newstack = (mrb_value *)mrb_realloc(mrb, mrb->c->stbase, sizeof(mrb_value) * size);
+  newstack = (mrb_value *)mrb_realloc_simple(mrb, mrb->c->stbase, sizeof(mrb_value) * size);
   if (newstack == NULL) {
     mrb_exc_raise(mrb, mrb_obj_value(mrb->stack_err));
   }