Fix inline comments

[mamaniv]

This commit solves an issue described in https://github.com/davidbonnet/astring/issues/562 It also contains a change in the relevant test.

[davidbonnet]

Thanks @mamaniv for suggesting this change. It's going in the right direction, however I'm afraid that the performance impact of filter calls with inline functions will be huge. An alternative that doesn't define inline functions (without going through the entire comments list every time) should be faster.