RFR: 8318364: Add an FFM-based implementation of harfbuzz OpenType layout

[Phil Race]

8318364: Add an FFM-based implementation of harfbuzz OpenType layout

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Commit messages:
 - remove tailing white space
 - use scaling
 - Fix windows build, remove perf. logging
 - Add test, fix bug
 - use allocateFrom
 - add offset param
 - suppressed restricted warnings, now builds but not running yet
 - Adapt to changed API for FFM final
 - Merge
 - Use exact VarHandles
 - ... and 7 more: https://git.openjdk.org/jdk/compare/77fa44fd...8d826865

Changes: https://git.openjdk.org/jdk/pull/15476/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15476&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8318364
  Stats: 1374 lines in 7 files changed: 1372 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/15476.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15476/head:pull/15476

PR: https://git.openjdk.org/jdk/pull/15476