build(rust): vendor rnix parser crate

third_party/crates/text-size-1.1.1/tests/indexing.rs

@@ -0,0 +1,8 @@
+use text_size::*;
+
+#[test]
+fn main() {
+    let range = TextRange::default();
+    _ = &""[range];
+    _ = &String::new()[range];
+}