Refactor specializer to not fold scalars

The specializer now correctly identifies when a compiled value is a
scalar and avoids folding it into a constant node. Instead, it updates
the callee to the specialized version if it's an object. This ensures
that scalar folding does not interfere with the program's execution.

src/ast/vm.rs

@@ -783,7 +783,7 @@ impl VM {
                     }
 
                     match &curr.kind {
-                        BoundKind::Constant(v) => self.stack.push(v.clone()),
+                        BoundKind::Constant(v) if !O::ACTIVE => self.stack.push(v.clone()),
                         _ => {
                             let val = self.eval_internal(obs, curr)?;
                             self.stack.push(val);