RFR: 8336356: [s390x] preserve Vector Register before using for string compress / expand [v3]

[Amit Kumar]

> This PR adds `TEMP` effect for the vector register, allotted by register allocator, used in the string compress/expand intrinsic. Also it enabled the Vector computation part of those intrinsics which was disabled by https://github.com/openjdk/jdk/pull/18162
> 
> tier1 test, which also includes string intrinsic tests `compiler/intrinsics/string/` are clean. No regression seen.

Amit Kumar has updated the pull request incrementally with one additional commit since the last revision:

  indentation fix in s390.ad file

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/22354/files
  - new: https://git.openjdk.org/jdk/pull/22354/files/3543e1c8..5c5079f6

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22354&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22354&range=01-02

  Stats: 6 lines in 1 file changed: 0 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/22354.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22354/head:pull/22354

PR: https://git.openjdk.org/jdk/pull/22354