build(rust): vendor googletest crate

third_party/crates/num-traits-0.2.19/build.rs

@@ -0,0 +1,7 @@
+fn main() {
+    let ac = autocfg::new();
+
+    ac.emit_expression_cfg("1f64.total_cmp(&2f64)", "has_total_cmp"); // 1.62
+
+    autocfg::rerun_path("build.rs");
+}