Integrated: Merge bworld

[Vicente Romero]

Merge bworld into bworld-apis

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Commit messages:
 - Merge bworld
 - Merge branch 'bworld' into bworld-apis_merge_bworld
 - Merge bworld
 - Merge bworld
 - Support preview features in libraries

The merge commit only contains trivial merges, so no merge-specific webrevs have been generated.

Changes: https://git.openjdk.org/valhalla/pull/2096/files
  Stats: 156 lines in 84 files changed: 15 ins; 2 del; 139 mod
  Patch: https://git.openjdk.org/valhalla/pull/2096.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/2096/head:pull/2096

PR: https://git.openjdk.org/valhalla/pull/2096