[jdk21u-dev] RFR: 8336827: compiler/vectorization/TestFloat16VectorConvChain.java timeouts on ppc64 platforms after JDK-8335860 [v4]

[Goetz Lindenmaier]

> I backport this to fix test failures caused by backport of JDK-8333890.
> 
> I include parts of JDK-8345146 that enable the test again. 
> JDK-8345146 implements the needed features for this test on PPC and was backported already.
> The test adaption for TestFloat16VectorConvChain was omitted as the test was not in 21 at that time.

Goetz Lindenmaier has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains four additional commits since the last revision:

 - Merge branch 'master' into goetz_backport_8336827
 - Parts of 8345146 missing as that was downported earlier
 - Backport 5b4824cf9aba297fa6873ebdadc0e9545647e90d
 - Backport 35df48e1b321d16f44ba924065143af67143cf95

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

Changes:
  - all: https://git.openjdk.org/jdk21u-dev/pull/1589/files
  - new: https://git.openjdk.org/jdk21u-dev/pull/1589/files/fd4b4cd2..9fac13eb

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=1589&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=1589&range=02-03

  Stats: 3568 lines in 49 files changed: 3515 ins; 13 del; 40 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/1589.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/1589/head:pull/1589

PR: https://git.openjdk.org/jdk21u-dev/pull/1589