RFR: 8296754: AutoCreateSharedArchive in JDK 20 is not compatible with JDK 19 [v7]

[Matias Saavedra Silva]

> The -XX:+AutoCreateSharedArchive flag was implemented in JDK 19, however, this flag doesn't work across JDK 19 and 20.
> 
> Expected: JDK 20 should recreate the specified CDS archive
> Actual: JDK 20 cannot recognize the archive file and gives up
> 
> The new field from GenericCDSFileMapHeader is now in FileMapHeader. Verified with tier 1-4 tests.

Matias Saavedra Silva has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains eight commits:

 - Merge branch 'master' into autoCreateSharedArchive_8296754
 - Added newline to end of test
 - Removed unused import
 - Test now passes
 - Changed whitespace and comment
 - Adjusted whitespace
 - Added test
 - 8296754: AutoCreateSharedArchive in JDK 20 is not compatible with JDK 19

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Changes: https://git.openjdk.org/jdk/pull/11148/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11148&range=06
  Stats: 249 lines in 8 files changed: 191 ins; 15 del; 43 mod
  Patch: https://git.openjdk.org/jdk/pull/11148.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11148/head:pull/11148

PR: https://git.openjdk.org/jdk/pull/11148