RFR: 8367993: G1: Speed up ConcurrentMark initialization [v3]

[Leo Korinth]

> This change moves almost all of the ConcurrentMark initialisation from its constructor to the method `G1ConcurrentMark::fully_initialize()`.  Thus, creation time of the VM can be slightly improved by postponing creation of ConcurrentMark. Most time is saved postponing creation of statistics buffers and threads.
> 
> It is not obvious that this is the best solution. I have earlier experimented with lazily allocating statistics buffers _only_. One could also initialise a little bit more eagerly (for example the concurrent mark thread) and maybe get a slightly cleaner change. However IMO it seems better to not have ConcurrentMark "half initiated" with a created mark thread, but un-initialised worker threads.
> 
> This change is depending on the integration of https://bugs.openjdk.org/browse/JDK-8373253.
> 
> I will be out for vacation, and will be back after new year (and will not answer questions during that time), but I thought I get the pull request out now so that you can have a look.

Leo Korinth has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 564 commits:

 - Merge branch '8373253' into 8367993
 - Merge branch 'master' into _8373253
 - Merge branch 'master' into _8367993
 - 8366058: Outdated comment in WinCAPISeedGenerator
   
   Reviewed-by: mullan
 - 8357258: x86: Improve receiver type profiling reliability
   
   Reviewed-by: kvn, vlivanov
 - 8373704: Improve "SocketException: Protocol family unavailable" message
   
   Reviewed-by: lucy, jpai
 - 8373722: [TESTBUG] compiler/vectorapi/TestVectorOperationsWithPartialSize.java fails intermittently
   
   Reviewed-by: jiefu, jbhateja, erfang, qamai
 - 8343809: Add requires tag to mark tests that are incompatible with exploded image
   
   Reviewed-by: alanb, dholmes
 - 8374465: Spurious dot in documentation for JVMTI ClassLoad
   
   Reviewed-by: kbarrett
 - 8374317: Change GCM IV size to 12 bytes when encrypting/decrypting TLS session ticket
   
   Reviewed-by: djelinski, mpowers, ascarpino
 - ... and 554 more: https://git.openjdk.org/jdk/compare/2aa8aa4b...28ccbb68

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Changes: https://git.openjdk.org/jdk/pull/28723/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28723&range=02
  Stats: 130308 lines in 3967 files changed: 83803 ins; 29735 del; 16770 mod
  Patch: https://git.openjdk.org/jdk/pull/28723.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28723/head:pull/28723

PR: https://git.openjdk.org/jdk/pull/28723