Compiler crashes when emitting declaration for malformed interface 

**TypeScript Version:** nightly, with `--declaration` flag, also reproducable with stable version
**Code**

```ts
// @declaration
class A{}
interface Class extends (typeof A){}
```

**Expected behavior:**
Report error like without `--declaration` flag.

**Actual behavior:** 
Crashes with `Cannot read property 'heritageClauses' of undefined` in `writeInterfaceDeclaration`