Code Example:
synchronized class Thing {
        void doSomeWork(void delegate() work) {
                work();
        }
        void work() {}
}

void main() {
        auto th = new Thing();
        th.doSomeWork(&th.work);
}

This example won't compile because the type of `&th.work` is `void delegate() shared`, which will not implicitly convert to `void delegate()`.
This type is probably correct - it's safe to share that delegate between threads, but since it's also safe to NOT share that delegate between threads, the delegate should implicitly cast to non-shared.

This is a large problem for code using shared data because `void delegate() shared` does not parse as a type.

The current workaround is to insert a cast to `void delegate()` at the call site.