Partially revert 86c68c7a2c971efe8e35b1f1bd99401dc8b688d2

Partially revert 86c68c7a2c971efe8e35b1f1bd99401dc8b688d2

That commit moved the advance adjustment for mark positioning to
be applied immediately, instead of doing late before.  This breaks
if mark advances are zeroed late, like in Arabic.  Also, easier to
hit it in RTL scripts since a single mark with non-zero advance is
enough to hit the bug, whereas in LTR, at least two marks are needed.

This reopens https://github.com/behdad/harfbuzz/issues/211
The cursive+mark interaction is broken again.  To be fixed in a
different way.