Cannot compile serde_json to Web Assembly with target-feature=+multivalue

[eastside]

The issue is that if you use serde_json and you're trying to compile to Web Assembly with multi-value returns turned on, a strange compilation error results.

I've made a minimum reproducible here which includes a complete description of the error.

Here's a rust-lang/rust thread on multivalue support that may prove useful. I'm not entirely sure if this is an issue more for Rust core, or if it's a serde_json issue (or a little of both?).

[dtolnay]

I don't know much about WebAssembly, but I am skeptical that this is a serde_json issue.