RFR: 8316746: Top of lock-stack does not match the unlocked object

[Martin Doerr]

In case of OSR compilations, `map()->peek_monitor_obj()` may return the objects in wrong order. We should use the popped object. I'm not changing the code for `LM_LEGACY`. That may be done separately.
Note that C1 uses the popped object, too: `case Bytecodes::_monitorexit    : monitorexit (apop(), s.cur_bci());`

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Commit messages:
 - 8316746: Top of lock-stack does not match the unlocked object

Changes: https://git.openjdk.org/jdk/pull/16345/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=16345&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8316746
  Stats: 11 lines in 2 files changed: 8 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/16345.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16345/head:pull/16345

PR: https://git.openjdk.org/jdk/pull/16345