RFR: 8273300: Check Mutex ranking during a safepoint [v5]

[Coleen Phillimore]

> This change checks lock ranking during a safepoint.  For some reason, safepoint checking was excluded, probably from the days where Safepoint_lock and Threads_lock were used.
> Because of checking during a safepoint, some locks had to get lower ranks.  The CR has the details of which locks these were.  The Service_lock complicates things because it's held during oops_do, which may take out other G1 locks.
> This was built and tested with Shenandoah.  Thanks to @zhengyu123 for the changes in Shenandoah.
> Tests run tier1-8.

Coleen Phillimore has updated the pull request incrementally with three additional commits since the last revision:

 - Revert copyright changes again
 - Revert "Revert unintended copyright changes."
   
   This reverts commit 712af5df87a5cefc16a9844867c3be1ae663b00d.
 - Revert unintended copyright changes.

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5467/files
  - new: https://git.openjdk.java.net/jdk/pull/5467/files/9920c227..eec9b842

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5467&range=04
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5467&range=03-04

  Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5467.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5467/head:pull/5467

PR: https://git.openjdk.java.net/jdk/pull/5467