RFR: 8349727: [PPC] C1: Improve Class.isInstance intrinsic

[Martin Doerr]

PPC64 implementation of [JDK-8337251](https://bugs.openjdk.org/browse/JDK-8337251).
The new runtime stub is called like a C function and therefore needs a `FunctionDescriptor` on PPC64 with ABIv1. The entry needs to be updated after relocation. I have used and enhanced the relocation code for that.

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Commit messages:
 - 8349727: [PPC] C1: Improve Class.isInstance intrinsic

Changes: https://git.openjdk.org/jdk/pull/23602/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23602&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8349727
  Stats: 102 lines in 3 files changed: 93 ins; 0 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/23602.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23602/head:pull/23602

PR: https://git.openjdk.org/jdk/pull/23602