Symbols for default exports are not printed correctly

[weswigham]

TypeScript Version: 2.6.0-dev.201xxxxx

Code
Initially, this was visible in our type baselines for an internal project, however I have a minimal sample here:

// @declaration: true
// @filename: component.ts
class Foo {}
export default Foo;

// @filename: test.ts
import * as Component from "./component";
export default Component.default;

Expected behavior:

// component.d.ts
declare class Foo {
}
export default Foo;
// test.d.ts
import * as Component from "./component";
declare const _default: typeof Component.default;
export default _default;

Actual behavior:

// component.d.ts
declare class Foo {
}
export default Foo;
// test.d.ts
import * as Component from "./component";
declare const _default: typeof Component.Foo;
export default _default;

Mentioned this to @Andy-MS the other day, since it looks like this behavior appeared awhile ago; I've bisected, and the issue first appears in 71f8852 (so a result of #18616), @Andy-MS care to take a look?