Add to-do for bignum integer parsing

crates/frontend/src/ast.rs

@@ -256,6 +256,7 @@ pub fn expr(db: &dyn Database, ast: AstNode) -> Expr {
         Value(match int.contents(db).to_string().parse() {
             Ok(val) => Integer(val),
             Err(_) => {
+                // TODO: use bignum
                 diagnostic::SimpleError::new(int, "failed to parse integer literal").accumulate(db);
                 Integer(0)
             }