Use `memset()` to clear stack unless `MRB_NAN_BOXING`.
MODIFY
src/vm.c
src/vm.c
@@ -102,17 +102,13 @@ void mrb_method_missing(mrb_state *mrb, mrb_sym name, mrb_value self, mrb_value
static inline void
stack_clear(mrb_value *from, size_t count)
{
-#ifndef MRB_NAN_BOXING
- const mrb_value mrb_value_zero = { { 0 } };
-
- while (count-- > 0) {
- *from++ = mrb_value_zero;
- }
-#else
+#ifdef MRB_NAN_BOXING
while (count-- > 0) {
SET_NIL_VALUE(*from);
from++;
}
+#else
+ memset(from, 0, sizeof(mrb_value)*count);
#endif
}

Use `memset()` to clear stack unless `MRB_NAN_BOXING`.