[jdk17u-dev] RFR: 8303742: CompletableFuture.orTimeout leaks if the future completes exceptionally [v2]

[Ben Taylor]

> Clean backport of a patch to prevent `CompleteableFuture.orTimeout` from leaking when a `ScheduledFutureTask` exits exceptionally
> 
> Passes the included test as well as jtreg tier 1 locally on linux x86_64
> 
> Updated to include JDK-8304557, which is a follow up item to prevent the test from timing out, see @RealCLanger's comment below. That backport is also clean.

Ben Taylor has updated the pull request incrementally with one additional commit since the last revision:

  Backport 6f67abd352ce9605dd93188995d42a47ee07b25e

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

Changes:
  - all: https://git.openjdk.org/jdk17u-dev/pull/3000/files
  - new: https://git.openjdk.org/jdk17u-dev/pull/3000/files/6ed87eff..e8dc6bc4

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=3000&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=3000&range=00-01

  Stats: 34 lines in 1 file changed: 20 ins; 0 del; 14 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/3000.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/3000/head:pull/3000

PR: https://git.openjdk.org/jdk17u-dev/pull/3000