perf: String() 有限 double 转串加 16 槽 last-value 缓存

crates/oxide_vm/src/vm/vmhost.rs

@@ -33,6 +33,9 @@ impl oxide_runtime_api::VmHost for Vm {
     fn new_string_owned(&mut self, s: String) -> JsValue {
         Vm::new_string_owned(self, s)
     }
+    fn number_to_string_cached(&mut self, d: f64) -> JsValue {
+        Vm::number_to_string_cached(self, d)
+    }
     fn new_bigint(&mut self, v: num_bigint::BigInt) -> JsValue {
         Vm::new_bigint(self, v)
     }