RFR: 8309129: AArch64: guarantee(T != T2S) failed: "incorrect arrangement" after JDK-8307795 [v2]

[Chang Peng]

> This patch fixes the issue introduced by JDK-8307795. Since addv[1] cannot support "T2S" SIMD arrangement, we should use addp[2] in this case.
> 
> TEST passed on AArch64:
> hotspot:compiler/vectorapi, jdk:jdk/incubator/vector, tier1-3
> 
> [1]: https://developer.arm.com/documentation/ddi0596/2020-12/SIMD-FP-Instructions/ADDV--Add-across-Vector-
> [2]: https://developer.arm.com/documentation/ddi0596/2020-12/SIMD-FP-Instructions/ADDP--vector---Add-Pairwise--vector--

Chang Peng 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 two additional commits since the last revision:

 - Merge branch 'openjdk:master' into fix_truecount
 - 8309129: AArch64: guarantee(T != T2S) failed: "incorrect arrangement" after JDK-8307795
   
   This patch fixes the issue introduced by JDK-8307795. Since addv[1]
   cannot support "T2S" SIMD arrangement, we should use addp[2] in this
   case.
   
   TEST passed on AArch64:
   hotspot:compiler/vectorapi, jdk:jdk/incubator/vector, tier1-3
   
   [1]: https://developer.arm.com/documentation/ddi0596/2020-12/SIMD-FP-Instructions/ADDV--Add-across-Vector-
   [2]: https://developer.arm.com/documentation/ddi0596/2020-12/SIMD-FP-Instructions/ADDP--vector---Add-Pairwise--vector--
   
   Change-Id: I2a224a24b83bbbb9289648d88351de6adb24b760

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/14245/files
  - new: https://git.openjdk.org/jdk/pull/14245/files/8fc40208..7736013f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14245&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14245&range=00-01

  Stats: 2107 lines in 159 files changed: 774 ins; 840 del; 493 mod
  Patch: https://git.openjdk.org/jdk/pull/14245.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14245/head:pull/14245

PR: https://git.openjdk.org/jdk/pull/14245