fix --declaration typechecking (complex case)

[sparecycles]

This fixes generation of typescriptServices.d.ts,
although this is not a current requirement
( #465 ).

I don't have a unit test yet. [EDIT: I added a unit test]

[EDIT] This PR fixes #466.

[sparecycles]

The purpose of using getParentOfSymbol is that the result is normalized through getMergedSymbol.

Later the symbols are identically compared and if they are not normalized to be the merged symbol the comparison will fail when it ought to succeed:
https://github.com/sparecycles/TypeScript/blob/fix/checker-declaration/src/compiler/checker.ts#L685

[sparecycles]

Here's a small test case which is fixed by this PR:

( To be added as a new baseline test case ) [EDIT: Done and done]

A.ts

module A { export interface I { } }

B.ts

/// <reference path="A.ts" />

module A { ; } // This module confuses the typechecker

module B {
    export function f(): A.I {
        return null;
    }
}

Pre-PR Result

node ../built/local/tsc.js B.ts --declaration --out out.js
B.ts(6,21): Return type of exported function has or is using private name 'A.I'.

[sparecycles]

Thanks @MaceWindu for pointing out that this fixes #446

[sheetalkamat]

👍