RFR: 8273754: Re-introduce Automatic-Module-Name in empty jars

[Abhinay Agarwal]

Re-introduce `Automatic-Module-Name` for empty jars until a better alternative to empty jars has been finalized.

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Commit messages:
 - 8273754: Re-introduce Automatic-Module-Name in empty jars

Changes: https://git.openjdk.java.net/jfx/pull/623/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=623&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8273754
  Stats: 5 lines in 1 file changed: 5 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jfx/pull/623.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/623/head:pull/623

PR: https://git.openjdk.java.net/jfx/pull/623