RFR: 8272609: Add string deduplication support to SerialGC [v2]

[Denghui Dong]

> Hi team,
> 
> Please help review this change to add string deduplication support to SerialGC.
> 
> Thanks,
> Denghui

Denghui Dong has updated the pull request incrementally with one additional commit since the last revision:

  avoid non-local variables with non-trivial / not-constexpr constructors or destructors

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5153/files
  - new: https://git.openjdk.java.net/jdk/pull/5153/files/5b9a5536..d7a7c68a

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5153&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5153&range=00-01

  Stats: 6 lines in 5 files changed: 1 ins; 0 del; 5 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5153.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5153/head:pull/5153

PR: https://git.openjdk.java.net/jdk/pull/5153