This disables fallback shaper in tiny builds.  Projects that don't
use our build system and want to disable fallback shaper (eg. Firefox)
should define HB_NO_FALLBACK_SHAPE now.

Part of https://github.com/harfbuzz/harfbuzz/issues/1652

https://github.com/googlefonts/harfbuzz/commit/9f610ae239a11e86f94621e26bc15849b65ce41b#commitcomment-33944686

Part of https://github.com/harfbuzz/harfbuzz/issues/1682

This reverts commit 47030b18.

Reverts only the hb-ft part, to reinstate non-OpenType kerning with
FreeType.

Fixes https://github.com/harfbuzz/harfbuzz/issues/1682

This reverts commit d219f899.

API change: Un-deprecate font kern API.

Part of https://github.com/harfbuzz/harfbuzz/issues/1682

We should document that this API is only necessary to hook up
non-OpenType kerning.  hb-ot-font will continue to NOT implement them.

add Unicode UCS-4 cmap
fix Unicode bits in OS/2
add Unicode cmap sub-table in SourceHanSans-Regular_subset.otf
regenerate cff subset test expected results

Added in 01dff1ea and 19256bef, this was targeted at older
msvc versions that don't support C99 but now as we require
C++11 we don't target places those envs thus removing this.

+this works on gcc 4.8 as well as default code path.

This reverts commit a0c49007.

Just testing bots.  Will finish based on results.

The only thing I need for a working wasm in a minimum libc,
otherwise I have to provide the very same qsort inside that libc

https://github.com/harfbuzz/harfbuzz/issues/1652

Fixes https://github.com/harfbuzz/harfbuzz/issues/1724

https://github.com/harfbuzz/harfbuzz/issues/1740

I guess all of its field will be initialized anyway here but lets make it more defensive

Causing -Wextra-semi-stmt build error when no primitive has chosen
Interesting that nobody has noticed it yet.

mingw.org's MinGW.

src/hb-algs.hh: Don't compile _BitScanForward and _BitScanReverse
for GCC >= 4.  mingw.org's MinGW doesn't have these functions.

src/hb-atomic.hh: MemoryBarrier does exist in mingw.org's MinGW,
but it is not a macro, it is an inline function.  __MINGW32_VERSION
is a macro that exists only in mingw.org's MinGW, so conditioning
on it should not affect MinGW64, where MemoryBarrier is a macro.

src/hb-uniscribe.cc: Define E_NOT_SUFFICIENT_BUFFER if it is not
defined (mingw.org's MinGW doesn't).

src/hb.hh: Don't include intrin.h for mingw.org's MinGW, since that
header is not available; instead, include windows.h.  Conditioned
on __MINGW32_VERSION to avoid affecting MinGW64.

Saves a few bytes.