RFR: 8273916: Remove 'special' ranking [v2]

[Coleen Phillimore]

> This change removes the special ranking and folds it into nosafepoint.  You have to look at commit #3 to see this actual part of the change that doesn't include JDK-8273915.
> This passes tier1-6 also.

Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:

  Add comment about ThreadSMRDelete_lock

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5563/files
  - new: https://git.openjdk.java.net/jdk/pull/5563/files/17988275..81c5feff

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5563&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5563&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5563.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5563/head:pull/5563

PR: https://git.openjdk.java.net/jdk/pull/5563