[hebrew] Zero mark advance by GDEF late

Seems to be what Uniscribe does.

At this point I think it's work checking our default...

Fixes Bug 76767 - Zeroing of advance of 2nd component of multiple
substitution with SBL Hebrew
https://bugs.freedesktop.org/show_bug.cgi?id=76767

Micro-test added.
4 files changed