TypeScript doesn't narrow out `undefined` after constructor call when callee is `any`

TypeScript doesn't seem to narrow the type of a variable correctly in cases where the constructor being called is typed as `any`. If the type of a variable includes `undefined` in its type signature, it's not narrowed out after a constructor call even though by definition (I think--correct me if I'm wrong) `new fn()` *must* always evaluate to an object if it doesn't throw first. **TypeScript Version:** 3.1.3 <!-- Search terms you tried before logging this (so others can find this issue more easily) --> **Search Terms:** constructor narrow **Code** ```ts let x: { [x: string]: any } | undefined; x = new (Object as any)(); // AFAIK `x` can't possibly be undefined after this point console.log(x.foo); // error: Object is possibly 'undefined'. ``` **Expected behavior:** No error. **Actual behavior:** Compile-time error: `Object is possibly 'undefined'.` **Playground Link:** http://www.typescriptlang.org/play/#src=let%20x%3A%20%7B%20%5Bx%3A%20string%5D%3A%20any%20%7D%20%7C%20undefined%3B%0D%0Ax%20%3D%20new%20(Object%20as%20any)()%3B%0D%0Aconsole.log(x.foo)%3B%0D%0A