Productize new async rewriter

We have made some internal changes to how mongosh processes the JavaScript code that it receives as input. (This affects the built-in shell in Compass and VSCode playground as well, if it matters). I don’t think we have previously documented the limitations that we were imposing on users. Luckily, there’s only few left, and it’s not going to be a common occurrence for people to encounter them, but we should document them: The results of database calls, directly or indirectly through other functions, cannot be used in three contexts, namely, inside class constructor functions, inside non-async generator functions, and inside callbacks to {{array.sort()}}. As a workaround, wrapping the access to db results in async functions or using async generator functions works, respectively. Concretely, this means: {code} // For constructors: // ------------------------ // This will not work class SomeClass {   constructor() {     this.value = db.coll.find();   } } // Neither will this function listEntries() { return db.coll.find(); } class SomeClass {   constructor() {     this.value = listEntries();   } } // But this can be used instead, if it also fits the purpose here: class SomeClass {   constructor() {     this.value = (async() => {       return db.coll.find();     })();   } } // For generator functions: // ------------------------ // This will not work function* someGenerator() {   yield db.coll.find(); } // Neither will this function listEntries() { return db.coll.find(); } function* someGenerator() {   yield listEntries(); } // But this can be used instead, if it also fits the purpose here: function listEntries() { return db.coll.find(); } async function* someGenerator() {   yield listEntries(); } // For array.sort: // ------------------------ // This will not work db.getCollectionNames().sort((coll1, coll2) => {   return db[coll1].estimatedDocumentCount() - db[coll2].estimatedDocumentCount()) }); // But this approach can be used instead (and is often more performant): db.getCollectionNames().map(collName => {   return { collName, size: db[collName].estimatedDocumentCount() }; }).sort((coll1, coll2) => {   return coll1.size - coll2.size; }).map(coll => coll.collName); {code}