[crac] RFR: 8354432: [CRaC] Timed waiting finishes early w.r.t. wall clock time [v2]

[Timofei Pushkin]

> This is an alternative to #209 that also fixes `TimedWaitingTest`.
> 
> The solution is to offset `os::javaTimeNanos()` using nanosecond-precision wall clock time instead of millisecond-precision. See the explanation in the related JBS issue.
> 
> I've run the test 100 times in CI and haven't witnessed it failing. To compare, without the fix it would usually fail in the first 5-10 runs.

Timofei Pushkin has updated the pull request incrementally with one additional commit since the last revision:

  Move docs to header

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

Changes:
  - all: https://git.openjdk.org/crac/pull/221/files
  - new: https://git.openjdk.org/crac/pull/221/files/4de87e38..5497193d

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=crac&pr=221&range=01
 - incr: https://webrevs.openjdk.org/?repo=crac&pr=221&range=00-01

  Stats: 35 lines in 2 files changed: 9 ins; 9 del; 17 mod
  Patch: https://git.openjdk.org/crac/pull/221.diff
  Fetch: git fetch https://git.openjdk.org/crac.git pull/221/head:pull/221

PR: https://git.openjdk.org/crac/pull/221