The s390 template interpreter currently uses call_VM with check_exceptions = false when calling InterpreterRuntime::monitorenter.

Async Exceptions don't get installed at this place because JRT_ENTRY_NO_ASYNC is used and InterpreterRuntime::monitorenter doesn't throw any Exceptions normally.

But there's a possibility to install an Exception:
- JVMTI supports post_monitor_contended_enter etc.
- Native function for MonitorContendedEnter is called via JNI
- Native code can install an Exception
- Exception should be handled after return from InterpreterRuntime::monitorenter

Other platforms support that. s390 should do so, too.