RFR: 8350398: [s390x] Relativize initial_sp/monitors in interpreter frames

[Amit Kumar]

s390x port for [JDK-8315966](https://bugs.openjdk.org/browse/JDK-8315966). 

This PR depends on https://github.com/openjdk/jdk/pull/23660 because index calculation macro will be added by that PR, which is being used by this one. 


// Frame slot index relative to fp
#define _z_ijava_idx(_component) \
        (_z_ijava_state_neg(_component) >> LogBytesPerWord)

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Commit messages:
 - Z_R0 will work
 - Merge branch 'master' into monitor_rel
 - fix sign extension
 - relativization for monitors

Changes: https://git.openjdk.org/jdk/pull/23708/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23708&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8350398
  Stats: 50 lines in 5 files changed: 34 ins; 7 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/23708.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23708/head:pull/23708

PR: https://git.openjdk.org/jdk/pull/23708