RFR: 8264735: Make dynamic dump repeatable [v3]

[Yumin Qi]

> Hi, Please review
> 
>   Currently after dynamic dump, dump time tables (`_dumptime_talbles, _dumptime_lambda_proxy_class_dictionary and _saved_shared_path_table`) are corrupted and could not be used for next dump. The patch clones the three tables, and after dump restore them so the next dump is possible. With the fix, jcmd VM.cds dynamic_dump can do multiple dump to the same live process.
> 
>   Tests: tier1,tier2,tier3,tier4
>   
>   Thanks
>   Yumin

Yumin Qi 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 four additional commits since the last revision:

 - Save SharedPathTable array for later reclaim, remove comments for ctors
 - Merge branch 'master' into jdk-8264735
 - Fix comments, added check holding for DumpTimeTable_lock
 - 8264735: Make dynamic dump repeatable

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/4646/files
  - new: https://git.openjdk.java.net/jdk/pull/4646/files/9b64a16f..28dfcaf0

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=4646&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=4646&range=01-02

  Stats: 21819 lines in 383 files changed: 7345 ins; 12735 del; 1739 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4646.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4646/head:pull/4646

PR: https://git.openjdk.java.net/jdk/pull/4646