Description:harfbuzz版本降低到2.7.2
Sig:harfbuzz
Feature or Bugfix:Feature
Binary Source:No
Signed-off-by: Nlancer <haoshuo@huawei.com>

IssueNo: https://gitee.com/openharmony/third_party_harfbuzz/issues/I4H06M
Feature or Bugfix: Feature
Binary Source:No
Signed-off-by: Nlizhiqi <lizhiqi1@huawei.com>

Fixes https://github.com/harfbuzz/harfbuzz/issues/1918

Hopefully doesn't break anyone...

I had specially exposed the API as I didn't know how to embed harfbuzz
easily elsewhere but now with harfbuzz.cc it has become very easy
and I don't like to see its use anywhere as it has a bad naming and
its Kashida adding is bogus and only useful to check where it should
be added, not visually useful however.

Fixes https://github.com/harfbuzz/harfbuzz/issues/1910

The change to `round` wasn't intended

Not have used it personally for a long time, lets remove it

Core Text seems to apply them to Latin text, but Uniscribe doesn’t.

See https://github.com/harfbuzz/harfbuzz/pull/1908#issuecomment-521819343

Fixes https://github.com/harfbuzz/harfbuzz/issues/1907

Needed for other works

Use hb_font_t coords directly

Set caret_count to zero as that is what we want to happen inside lcar when
there is no result.

I *think* it should fix https://github.com/harfbuzz/harfbuzz/issues/1901

Ie. if on a system, alignof(void*) < sizeof(void*)...

https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6opbd.html

It has a different semantic, maybe we should just do a zero memset,
letting Behdad to decide.