RFR: 8261998: Remove unused shared entry support from utilities/hashtable [v2]

[Kim Barrett]

> Please review this small cleanup in the utilities/hashtable facility.  The
> support for "shared" entries is no longer needed or used, so is being deleted.
> 
> Testing:
> mach5 tier1-4 (some CDS tests are in tier4)

Kim Barrett has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains two additional commits since the last revision:

 - Merge branch 'master' into ht_shared
 - remove shared entry support

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/2638/files
  - new: https://git.openjdk.java.net/jdk/pull/2638/files/4ebdd71a..bf811b54

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=2638&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=2638&range=00-01

  Stats: 3323 lines in 88 files changed: 2061 ins; 627 del; 635 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2638.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2638/head:pull/2638

PR: https://git.openjdk.java.net/jdk/pull/2638