RFR: 8304074: [JMX] Add an approximation of total bytes allocated on the Java heap by the JVM [v28]

[Paul Hohensee]

> Please review this addition to com.sun.management.ThreadMXBean that returns the total number of bytes allocated on the Java heap since JVM launch by both terminated and live threads.
> 
> Because this PR adds a new interface method, I've updated the JMM_VERSION to 4, but would be happy to update it to 3_1 instead.

Paul Hohensee has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 100 commits:

 - 8304074: Remove extra file
 - 8304074: Add getTotalAllocatedBytes high water mark
 - Merge branch 'master' into 8304074
 - 8304074: Refactor test exception handling
 - Merge master
 - Merge master
 - 8304074: Change UnsupportedOperationException in javadoc comment to {@code UnsupportedOperationException}
 - 8306507: [linux] Print number of memory mappings in error reports
   
   Reviewed-by: adinn, sgehwolf
 - 8300086: Replace NULL with nullptr in share/c1/
   
   Reviewed-by: thartmann, chagedorn
 - 8308465: Reduce memory accesses in AArch64 MD5 intrinsic
   
   Reviewed-by: aph, phh
 - ... and 90 more: https://git.openjdk.org/jdk/compare/77c5adb0...5f2f86bb

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Changes: https://git.openjdk.org/jdk/pull/13814/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13814&range=27
  Stats: 297 lines in 10 files changed: 219 ins; 45 del; 33 mod
  Patch: https://git.openjdk.org/jdk/pull/13814.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13814/head:pull/13814

PR: https://git.openjdk.org/jdk/pull/13814