RFR: 8349686: [s390x] C1: Improve Class.isInstance intrinsic [v6]

[Amit Kumar]

> s390x implementation for Class.isInstance intrinsic. 
> 
> Tier1 test on release & fastdebug vm are clean with flag: `-XX:-UseSecondarySupersCache -XX:+UseSecondarySupersTable -XX:+VerifySecondarySupers -XX:+StressSecondarySupers`. 
> 
> Benchmark results will be updated soon.

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

  fixes older hardware issues

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/23535/files
  - new: https://git.openjdk.org/jdk/pull/23535/files/fdd979a8..8bf5b92a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23535&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23535&range=04-05

  Stats: 31 lines in 3 files changed: 28 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/23535.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23535/head:pull/23535

PR: https://git.openjdk.org/jdk/pull/23535