RFR: 8354969: Add strdup function for ResourceArea [v4]

[Anton Artemov]

> Added a strdup() method, as requested by the bug reporter. The method is added to Arena, but also available in ResourceArea, as requested. A test for the method is provided. 
> 
> Testing: tiers 1-3 on multiple platforms.

Anton Artemov has updated the pull request incrementally with one additional commit since the last revision:

  8354969: Addressed reviewrs comments

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/24998/files
  - new: https://git.openjdk.org/jdk/pull/24998/files/0c57dee8..155fd3ed

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24998&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24998&range=02-03

  Stats: 33 lines in 8 files changed: 9 ins; 18 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/24998.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24998/head:pull/24998

PR: https://git.openjdk.org/jdk/pull/24998