"is not a constructor" should be detected in compile time as "used before its declaration."

TypeScript Version: 3.2.2
This repository demonstrates that I run in to the issue in ts@next.
https://github.com/qballer/tsbug

Search Terms:
constructor, lexical scope, run time error vs compile time
Code

const b = getB() 

function getB() {
    // will throw C is not a constructor in runtime 
    return new C() // ** 
}

// Will generate:  Class 'C' used before its declaration.
// const instanceOfC = new C()

class C {}

Expected behavior:
Should generate: Class 'C' used before its declaration.

Actual behavior:
Explodes in runtime with 'is not a constructor' error.

Playground Link:
Playground
Repo

Related Issues:

Start with the reproduction code in the linked qballer/tsbug repository and the TypeScript Playground example, then compare the existing diagnostic for const instanceOfC = new C() with the getB() case. Done means the compiler reports "Class 'C' used before its declaration" for the constructor call instead of allowing the runtime "is not a constructor" failure.