Handle directive inside a statement

[virzak]

Handle directive inside statements aren't handled properly. First mentioned in #83

        [Zomp.SyncMethodGenerator.CreateSyncVersion(OmitNullableDirective = true)]
        public async Task FooAsync()
        {
            await Task.Delay(100);

            var bar =
#if DEBUG
                true;
#else
                false;
#endif
        }