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/compiler/mod.rs

@@ -1,5 +1,7 @@
 pub mod binder;
 pub mod bound_nodes;
+pub mod tco;
 
 pub use binder::*;
 pub use bound_nodes::*;
+pub use tco::*;