The javascript polyflll function random_get calls an undefined function __wasm_random_get and gives an error. Calling the ___wasi_random_get function with 3 underscores would generate a random number without errors. Most of the other WASI functions seem to have 3 underscores so why doesn't this function have them? The sched_yield and sock_shutdown functions also seem to be calling undefined functions.
https://github.com/CraneStation/wasmtime/blob/a6f31a2be331f66a26e5516cae80c02261b49744/wasmtime-wasi/js-polyfill/wasi.js#L455