RFR: 8334026: Provide a diagnostic PrintMemoryMapAtExit switch on Linux

[Thomas Stuefe]

To investigate footprint problems of processes with a short lifespan (e.g. startup footprint problems), we found it very useful to be able to get an annotated memory map at exit - the same map printed by jcmd System.map.

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Commit messages:
 - fix whitespaces
 - JDK-8334026-Provide-a-diagnostic-PrintMemoryMapAtExit-switch-on-Linux

Changes: https://git.openjdk.org/jdk/pull/19660/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19660&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8334026
  Stats: 68 lines in 4 files changed: 63 ins; 4 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/19660.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19660/head:pull/19660

PR: https://git.openjdk.org/jdk/pull/19660