Some clang versions define static_assert as a macro apparently, so we cannot
redefine it...

This reverts commit 94bfea0c.
This reverts commit 4e626278.

So we don't accidentally break it again.

Use rand=255 to mean "randomize".

Part of https://github.com/harfbuzz/harfbuzz/pull/803

Randomization only happens by default. If the user specifies a value for
'rand', that value is respected.

Sorry for the noise, downstream custom builders.  Please adjust.

Ouch!

Support 128bit type.

Fixes https://github.com/harfbuzz/harfbuzz/issues/712

Not all shapers code is updated to set this properly.
GSUB and Arabic shaper are updated.
GPOS and other shapers are NOT.

Fixes https://github.com/behdad/harfbuzz/issues/224

Not used yet.

Shape-plan caching is not implemented.

In prep for more changes.

Limits number of alternatives per glyph per feature to 255, so be it.
That's better than possibly breaking shaping because of one bad feature
value.

This one:

  map->mask = (1 << (next_bit + bits_needed)) - (1 << next_bit);

before the fix, the shift was done as an int, causing overflow
if it ever got to 1 << 31.  Sprinkle 'u's around.

Fixes https://bugs.chromium.org/p/chromium/issues/detail?id=634805

Originally the way Jonathan had written this was correct in
"continue"ing:

https://github.com/jfkthame/harfbuzz/commit/35e28c7a733eaffcd9f062b18d7db9fbb3d990fc#diff-ead86a33a5cc9ad7f6e6381031a0baddR199

When I rewrote his patch, I messed it up:

https://github.com/behdad/harfbuzz/commit/da132937989acb4d8ca9bd41c79f98750e7dda30#diff-ead86a33a5cc9ad7f6e6381031a0baddR209

the intended behavior was NOT to set found=TRUE and NOT to continue.
This was resulting in feature_index[table_index] being left unset.
Oops!

Fixes https://github.com/behdad/harfbuzz/issues/63

https://bugzilla.mozilla.org/show_bug.cgi?id=986802
Fixes https://github.com/behdad/harfbuzz/pull/39

API Change:

-hb_ot_layout_language_get_required_feature_index
+hb_ot_layout_language_get_required_feature

New API takes an extra pointer argument.  Pass NULL in to get
behavior of previous API.

Reworked by behdad

In an effort to make the algorithm used clear.

Patch from Emil Eklund.

Filter them out when compiling map.

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...

After the Ngapi hackfest work, we were assuming that fonts
won't use presentation features to choose specific forms
(eg. conjuncts).  As such, we were using auto-joiner behavior
for such features.  It proved to be troublesome as many fonts
used presentation forms ('pres') for example to form conjuncts,
which need to be disabled when a ZWJ is inserted.

Two examples:

	U+0D2F,U+200D,U+0D4D,U+0D2F with kartika.ttf
	U+0995,U+09CD,U+200D,U+09B7 with vrinda.ttf

What we do now is to never do magic to ZWJ during GSUB's main input
match for Indic-style shapers.  Note that backtrack/lookahead are still
matched liberally, as is GPOS.  This seems to be an acceptable
compromise.

As to the bug that initially started this work, that one needs to
be fixed differently:

  Bug 58714 - Kannada u+0cb0 u+200d u+0ccd u+0c95 u+0cbe does not
  provide same results as Windows8
  https://bugs.freedesktop.org/show_bug.cgi?id=58714

New numbers:

BENGALI: 353689 out of 354188 tests passed. 499 failed (0.140886%)
DEVANAGARI: 707305 out of 707394 tests passed. 89 failed (0.0125814%)
GUJARATI: 366349 out of 366457 tests passed. 108 failed (0.0294714%)
GURMUKHI: 60706 out of 60747 tests passed. 41 failed (0.067493%)
KANNADA: 951030 out of 951913 tests passed. 883 failed (0.0927606%)
KHMER: 299070 out of 299124 tests passed. 54 failed (0.0180527%)
LAO: 53611 out of 53644 tests passed. 33 failed (0.0615167%)
MALAYALAM: 1048102 out of 1048334 tests passed. 232 failed (0.0221304%)
ORIYA: 42320 out of 42329 tests passed. 9 failed (0.021262%)
SINHALA: 271666 out of 271847 tests passed. 181 failed (0.0665816%)
TAMIL: 1091753 out of 1091754 tests passed. 1 failed (9.15957e-05%)
TELUGU: 970555 out of 970573 tests passed. 18 failed (0.00185457%)
TIBETAN: 208469 out of 208469 tests passed. 0 failed (0%)

Surprisingly, if user ever tried to turn a default feature off partially
(say, disable liga for a range), the feature was being turned off
globally!  Fixed now.