RFR: 8264735: Make dynamic dump repeatable [v2]

[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 incrementally with one additional commit since the last revision:

  Fix comments, added check holding for DumpTimeTable_lock

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/4646/files
  - new: https://git.openjdk.java.net/jdk/pull/4646/files/6245a80e..9b64a16f

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=4646&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=4646&range=00-01

  Stats: 5 lines in 3 files changed: 1 ins; 0 del; 4 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