Use before definition errors should not be reported in ambient contexts

[mhegazy]

// test.d.ts

declare var S: typeof A; // error TS2448: Block-scoped variable 'A' used before its declaration.
declare const A: number;  

Errors make sense only in non-ambient context.

[mihailik]

I would argue there should not be an error here too:

var S: typeof A;
const A: number;

We're not using A variable, we're using its type. And the type is known regardless of the order of the statements.