Just reimplement those JS string builtins in another host environment and provide it as a Wasm library. Stringref was basically just proposing pushing JS strings down into Wasm, which many in the CG saw as a big chunk of one specific platform just moving down a layer, into the engine.
Having used and implemented stringref and having seen the built-ins proposal I really think stringref is a much better developer experience and the CG is wrong. The built-ins are better than nothing but it's a terrible hack.
