optimize(env): single arg

src/ty/internal/mod.rs

@@ -485,7 +485,7 @@ pub struct Thunk<'jit, 'vm> {
 
 #[derive(Debug, IsVariant, Unwrap, Clone)]
 pub enum _Thunk<'jit, 'vm> {
-    Code(&'vm OpCodes, OnceCell<LetEnv<'jit, 'vm>>),
+    Code(&'vm OpCodes, OnceCell<Rc<LetEnv<'jit, 'vm>>>),
     SuspendedFrom(*const Thunk<'jit, 'vm>),
     Value(Value<'jit, 'vm>),
 }
@@ -497,7 +497,7 @@ impl<'jit, 'vm> Thunk<'jit, 'vm> {
         }
     }
 
-    pub fn capture(&self, env: LetEnv<'jit, 'vm>) {
+    pub fn capture(&self, env: Rc<LetEnv<'jit, 'vm>>) {
         if let _Thunk::Code(_, envcell) = &*self.thunk.borrow() {
             envcell.get_or_init(|| env);
         }