Unhelpful `--strictFunctionTypes` error when first method is `self(): this;`

**TypeScript Version:** 2.7.0-dev.20171214 **Code** ```ts declare class C<T> { self(): this; covariant(): T; contravariant: (t: T) => void; m(other: C<{}>): void; } new C<number>().m(new C<number>()); ``` **Expected behavior:** Error that `C<number>` isn't `C<{}>` because `C<{}>`'s `contravariant` can accept `(t: {})` but `C<number>` can only accept `(t: number)`. **Actual behavior:** ```ts src/a.ts(8,19): error TS2345: Argument of type 'C<number>' is not assignable to parameter of type 'C<{}>'. Types of property 'self' are incompatible. Type '() => C<number>' is not assignable to type '() => C<{}>'. Type 'C<number>' is not assignable to type 'C<{}>'. ```