[crac] RFR: DNS cache maintenance [v2]

[Radim Vansa]

> This draft PR contains a backport of issue that prevents compilation on systems with newer glibc versions; ideally the backport should be integrated first and then this PR can be rebased.

Radim Vansa has updated the pull request incrementally with one additional commit since the last revision:

  Fix test name in jtreg annotations

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Changes:
  - all: https://git.openjdk.org/crac/pull/40/files
  - new: https://git.openjdk.org/crac/pull/40/files/819c60b8..31a1943b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=crac&pr=40&range=01
 - incr: https://webrevs.openjdk.org/?repo=crac&pr=40&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/crac/pull/40.diff
  Fetch: git fetch https://git.openjdk.org/crac pull/40/head:pull/40

PR: https://git.openjdk.org/crac/pull/40