Mozilla Bug 873902 - Display Arabic text with diacritics is bad
https://bugzilla.mozilla.org/show_bug.cgi?id=873902

Fixes previous commit's test.

Failing now.

Bug 64476 - Typo in hb_set_t.get_min()

Some infrastructures use DEBUG as a generic symbol.

This is not ideal as we don't like -L/usr/lib in our linker line.
But this is only relevant to environments that don't have pkgconfig
files for ICU...

https://github.com/behdad/harfbuzz/pull/2

Sigh..

Bug 64039 - undefined macro AM_PROG_AR

The compile() function is starting to become illegible...

We always push a pause at the end such that each lookup falls in exactly
one pause_map_t.  Now, only if I can find a better name for that...

Saves another 3 / 4 percent with Amiri.

Not measurable by any means, but conceptually this is faster since
the mask matches more often than the digest.

Wasn't correct with the new combiner.  I should add it back somehow,
but for now the digests seem to be working very well...

Was unused.

Make Amiri rendering faster a whopping 45% again!  Speends up pretty
much anything I tested.

Correctly this time.

We were not initializing the digests properly and as a result they were
being initialized to zero, making digest1 to never do any useful work.

Speeds up Amiri shaping significantly.

This reverts commit 3d1b66a3.

The calculations were buggy.  It's not worth optimizing right now.

Useful for profiling shapers.

Just to be sure it's not punishing the old shaper performance
numbers.  Doesn't seem to have a measurable effect.