RFR: 8247872: Upgrade HarfBuzz to the latest 2.7.2

[Phil Race]

This upgrades JDK to import the current 2.7.2 version of harfbuzz - an OpenType text shaping library

https://bugs.openjdk.java.net/browse/JDK-8247872

This has passed building and headless and headful automated tests on all platforms.

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Commit messages:
 - 8247872: Upgrade HarfBuzz to the latest 2.7.2

Changes: https://git.openjdk.java.net/jdk/pull/993/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=993&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8247872
  Stats: 44663 lines in 207 files changed: 25198 ins; 12729 del; 6736 mod
  Patch: https://git.openjdk.java.net/jdk/pull/993.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/993/head:pull/993

PR: https://git.openjdk.java.net/jdk/pull/993