feat: Add tail call optimization

Introduce a TCO pass to the compiler and modify the VM to handle tail
calls.
This allows for deep recursion without stack overflow.

src/ast/environment.rs

@@ -6,6 +6,8 @@ use crate::ast::parser::Parser;
 use crate::ast::compiler::binder::Binder;
 use crate::ast::vm::VM;
 
+use crate::ast::compiler::tco::TCO;
+
 pub struct Environment {
     pub global_names: Rc<RefCell<HashMap<String, (u32, StaticType)>>>,
     pub global_values: Rc<RefCell<Vec<Value>>>,
@@ -115,9 +117,12 @@ impl Environment {
 
         // 3. Bind & Type Check
         let mut binder = Binder::new(self.global_names.clone());
-        let bound_ast = binder.bind(&untyped_ast)?;
+        let mut bound_ast = binder.bind(&untyped_ast)?;
 
-        // 4. Execute
+        // 4. Optimize
+        bound_ast = TCO::optimize(bound_ast);
+
+        // 5. Execute
         let mut vm = VM::new(self.global_values.clone());
         vm.run(&bound_ast)
     }