Even without FT or OT font funcs implementing get_nominal_glyphs(), there's measurable
speedup.

Fixes https://github.com/harfbuzz/harfbuzz/issues/1216

New API:
hb_buffer_set_invisible_codepoint()
hb_buffer_get_invisible_codepoint()

hb-shape / hb-view --invisible-codepoint

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.

Technically, static const needs an out-of-class definition.  Eg:

  CXXLD    libharfbuzz-subset.la
Undefined symbols for architecture x86_64:
  "OT::FeatureVariationRecord::min_size", referenced from:
      bool OT::GSUBGPOS::subset<OT::PosLookup>(hb_subset_context_t*) constin libharfbuzz_subset_la-hb-subset.o
      bool OT::GSUBGPOS::subset<OT::SubstLookup>(hb_subset_context_t*) constin libharfbuzz_subset_la-hb-subset.o
  "OT::Record<OT::LangSys>::min_size", referenced from:
      OT::Script::subset(hb_subset_context_t*) constin libharfbuzz_subset_la-hb-subset.o
  "OT::IntType<unsigned short, 2u>::min_size", referenced from:
      OT::Script::subset(hb_subset_context_t*) constin libharfbuzz_subset_la-hb-subset.o
      OT::RecordListOf<OT::Feature>::subset(hb_subset_context_t*) const  in libharfbuzz_subset_la-hb-subset.o
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status
make[4]: *** [libharfbuzz-subset.la] Error 1
make[3]: *** [all-recursive] Error 1
make[2]: *** [all] Error 2
make[1]: *** [all-recursive] Error 1
make: *** [all] Error 2
Exited with code 2

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

Finally, unified!

Towards possibly using Null pool for some nil objects.

Fixes #791.

line 323: Warning: info hides hb_buffer_t::info
...

Previously we made CGJ unskippable.  Now, if CGJ did NOT prevent
any reordering, allow skipping over it.  To make this work we
had to make changes to the Arabic mark reordering algorithm
implementation to renumber moved MCM marks.  See comments.

Fixes https://github.com/harfbuzz/harfbuzz/issues/554

This only counts recursions right now.  Good start.

Hopefully...
Fixes https://github.com/behdad/harfbuzz/issues/429

Fixes https://github.com/behdad/harfbuzz/issues/615

We'll see which bots I broke.

Based on patch from Jonathan Kew.

Needs more cleaning up and documentation.

New API:
hb_buffer_diff_flags_t
hb_buffer_diff()

Makes consumption easier.

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

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

This makes defining HB_NDEBUG much less relevant, to the
point of irrelevance.  Sorry about all the fuss in previous
release!

API changes:
- If NDEBUG is defined, define HB_NDEBUG
- Disable costlier sanity checks if HB_NDEBUG is defined.

In 1.2.3 introduced some code to disable costly sanity checks if
NDEBUG is defined.  NDEBUG, however, disables all assert()s as
well.  With HB_NDEBUG, one can disable costlier checks but keep
assert()s.

I'll probably add a way to define HB_NDEBUG automatically in
release tarballs.  But for now, production systems that do NOT
define NDEBUG, are encouraged to define HB_NDEBUG for our build.

Saves some sweet time and binary size!

Part of fixing https://github.com/behdad/harfbuzz/issues/211

Currently just announces lookup applications.  Message-API *will* change.
hb-shape / hb-view are updated to print-out messages to stder if --debug
is specified.

This reverts commit f0599db7.

Commit abadc171 provides a better
fix for this.

This reverts commit 68b507a3.

Commit abadc171 provides a better
fix for this.

Use the DEFINE_ENUM_FLAG_OPERATORS macro in winnt.h on Visual Studio,
which defines the bitwise operators for the enumerations that we want to
mark as hb_mark_as_flags_t, which will take care of the situation on newer
Visual Studio (>= 2012), where the build breaks with C2057 errors as the
underlying types of the enumerations is not clear to the compiler when we
do a bitwise op within the declaration of the enumerations themselves.

Also disable the C4200 (nonstandard extension used : zero-sized array in
struct/union) and C4800 ('type' : forcing value to bool 'true' or 'false'
(performance warning)) warnings as the C4200 is the intended scenario and
C4800 is harmless but is so far an unavoidable side effect of using
DEFINE_ENUM_FLAG_OPERATORS.

Fixes https://github.com/behdad/harfbuzz/issues/161

https://github.com/behdad/harfbuzz/issues/161