Interface merging silently fails with ES6 module syntax

[weswigham]

a.ts:

export interface Foo {
  a: string;
}

b.ts:

import {Foo} from "./a.ts";
export interface Foo {
  b?: number;
}

let x: Foo;

x will only have the members from the initial Foo declaration in a.ts.

[mhegazy]

this should be an error. an import does not merge with anything.