feat(jit): fib!

src/stack.rs

@@ -45,8 +45,8 @@ impl<T, const CAP: usize> Stack<T, CAP> {
     }
 
     pub fn pop(&mut self) -> T {
+        let item = self.items.get_mut(self.top - 1).unwrap();
         self.top -= 1;
-        let item = self.items.get_mut(self.top).unwrap();
 
         // SAFETY: `item` at `self.top` was previously written and is initialized.
         // We replace it with `MaybeUninit::uninit()` and then `assume_init`