RFR: JDK-8301998: Update HarfBuzz to 7.0.1 [v2]

[Harshitha Onkar]

> HarfBuzz library updated from v4.4.1 to v7.0.1
> 
> - harfbuzz.md file updated
> - Added -DHB_NO_VISIBILITY to HARFBUZZ_CFLAGS in Awt2DLibraries.gmk to avoid build issues on linux and macos targets.
> - GPOS.hh moved to Layout to Layout/GPOS to match upstream changes.
> - hb-ot-color-* files moved to OT/Color to match upstream changes.
> - 41 newly added, 8 deleted and 224 modified files (src + harfbuzz.md).

Harshitha Onkar has updated the pull request incrementally with one additional commit since the last revision:

  Updating.txt changes

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/12913/files
  - new: https://git.openjdk.org/jdk/pull/12913/files/a256318b..9c27df78

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12913&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12913&range=00-01

  Stats: 103 lines in 1 file changed: 61 ins; 17 del; 25 mod
  Patch: https://git.openjdk.org/jdk/pull/12913.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12913/head:pull/12913

PR: https://git.openjdk.org/jdk/pull/12913