feat: Add stack size to runtime metadata

Store the pre-calculated stack size of lambda bodies in the
RuntimeMetadata. This allows the VM to directly access this information
without recalculating it.

src/ast/vm.rs

@@ -508,7 +508,7 @@ impl VM {
                 for addr in upvalues {
                     captured.push(self.capture_upvalue(*addr)?);
                 }
-                let stack_size = body.calculate_stack_size();
+                let stack_size = node.ty.stack_size;
                 let closure = Closure::new(
                     params.ty.original.clone(),
                     body.ty.original.clone(),