Not allowed to await non-async chain

[coolaj86]

Each await chain MUST be on its own line.

An "await chain" is

• any statement that starts with await
  and terminates when
• the result of a return is not a promise
• (or when it's the end of the line).

Bug

Intuitively you'd think these should work as await signals that the interpreter should resolve all promises in the chain... but 'tis not so!

// error, oppsSync is not a property of the return value
let foo = await buildAsyncChain().buildMore().oopsSync().result;

// same as above
let bar = await doAsyncStuff().oopsSync().asyncMore();

Good Example

This is the desired, non-buggy behavior:

let fooPartial = await buildAsyncChain().buildMore().asyncStuff();
let foo = stuff.oopsSync().result;

let barPartial = await doAsyncStuff();
let bar = await barPartial.oopsSync().asyncMore();

Bad Example

let foo = (await doSyncStuff().asyncStuff()).oopsSync();

let bar = await (await doAsyncStuff()).oopsSync().asyncMore();