Async await syntax breaks in compiled JS when declaring an async closure inside a loop that has access to a scoped value

[JonoPrest]

There seems to be a bug that's reproduceable when you have a loop (for or while) and an async closure inside of it (defined using async await) that has access to a value that's scoped outside of the closure but inside of the loop.

I've tried it on rescript 10.1.4 and 11.0.0-rc.4 and both yield a javascript function where the await keyword is used inside of a non-async function.

//Demo.res file:
let topLevelAsyncFunction = async () => {
  for innerScopeVal in 0 to 3 {
    let asyncClosureAccessingScopedVal = async () => {
      Js.log2("Accessing scoped var inside loop", innerScopeVal)
      await Js.Promise.resolve()
    }

    await asyncClosureAccessingScopedVal()
  }
}

//Demo.bs.js compiled js file:
// Generated by ReScript, PLEASE EDIT WITH CARE


async function topLevelAsyncFunction() {
  for(var innerScopeVal = 0; innerScopeVal <= 3; ++innerScopeVal){
    var asyncClosureAccessingScopedVal = (async function(innerScopeVal){
    return function asyncClosureAccessingScopedVal() {
      console.log("Accessing scoped var inside loop", innerScopeVal);
      return await Promise.resolve(undefined);  /***<-- HERE it is using "await" keyword inside non async function ***/
    }
    }(innerScopeVal));
    await asyncClosureAccessingScopedVal(undefined);
  }
}

export {
  topLevelAsyncFunction ,
}
/* No side effect */

[cristianoc]

Probably one more instance of this kind: 1e0e325

[cristianoc]

@JonoPrest see PR #6479