RFR: 8352065: [PPC64] C2: Implement PopCountVL, CountLeadingZerosV and CountTrailingZerosV nodes [v2]

[David Linus Briemann]

> VectorCastL2X was not added due to bad performance and thus the bit count instructions are only vectorized for `int` but not for `long`.

David Linus Briemann has updated the pull request incrementally with one additional commit since the last revision:

  disable TestVectorPopcountVectorLong on power again

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/24064/files
  - new: https://git.openjdk.org/jdk/pull/24064/files/a3f027f5..afca9b3d

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24064&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24064&range=00-01

  Stats: 4 lines in 1 file changed: 0 ins; 2 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/24064.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24064/head:pull/24064

PR: https://git.openjdk.org/jdk/pull/24064