[crac] RFR: Report checkpoint processing to jcmd [v17]

[Ilarion Nakonechnyy]

> pass output stream from diagnosticCommand.cpp through java code into os_linux.cpp::VM_crac::doit()

Ilarion Nakonechnyy has updated the pull request incrementally with three additional commits since the last revision:

 - Skip an assert in
   LinuxAttachOperation::effectively_complete
   if it was called from crac checkpoint handling
 - corrected initialization ordering
 - review notes

-------------

Changes:
  - all: https://git.openjdk.org/crac/pull/10/files
  - new: https://git.openjdk.org/crac/pull/10/files/ccf84467..fe6fab9e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=crac&pr=10&range=16
 - incr: https://webrevs.openjdk.org/?repo=crac&pr=10&range=15-16

  Stats: 28 lines in 4 files changed: 9 ins; 4 del; 15 mod
  Patch: https://git.openjdk.org/crac/pull/10.diff
  Fetch: git fetch https://git.openjdk.org/crac pull/10/head:pull/10

PR: https://git.openjdk.org/crac/pull/10