RFR: 8253909: Implement detailed map file for CDS

[Ioi Lam]

For analyzing the contents of a CDS archive, we need a "map file" that describes the archive in different levels of
detail. This can be done using unified logging. E.g.,

java -Xshare:dump -Xlog:cds+map=trace:file=cds.map:none:filesize=0

For example, we can use the map file for troubleshooting [JDK-8253495](https://bugs.openjdk.java.net/browse/JDK-8253495)
(runtime/cds/DeterministicDump.java broken). We can diff two different cds.map files to see where the non-deterministic
contents come from.

See attachments in [JDK-8253909](https://bugs.openjdk.java.net/browse/JDK-8253909) for example map files at the
info/debug/trace levels.

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Commit messages:
 - 8253909: Implement detailed map file for CDS

Changes: https://git.openjdk.java.net/jdk/pull/474/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=474&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8253909
  Stats: 305 lines in 8 files changed: 265 ins; 9 del; 31 mod
  Patch: https://git.openjdk.java.net/jdk/pull/474.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/474/head:pull/474

PR: https://git.openjdk.java.net/jdk/pull/474