[jdk11u-dev] RFR: 8286707: JFR: Don't commit JFR internal jdk.JavaMonitorWait events

[Goetz Lindenmaier]

I backport this for parity with 11.0.20-oracle.

Trivial resolves in 
src/hotspot/share/jfr/support/jfrIntrinsics.hpp
src/hotspot/share/runtime/objectMonitor.cpp
src/jdk.jfr/share/classes/jdk/jfr/internal/JVM.java

src/jdk.jfr/share/classes/jdk/jfr/internal/RequestEngine.java
Skipped change to setFlushInterval() as method is not in 11.
That was added by "8226511: Implement JFR Event Streaming".

I had to define NOT_JFR_RETURN_ and change a nullptr occurance.

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Commit messages:
 - Backport fc889577eaf3f564d896818c1d9b1eb6fa5a8758

Changes: https://git.openjdk.org/jdk11u-dev/pull/2218/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=2218&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8286707
  Stats: 32 lines in 6 files changed: 24 ins; 3 del; 5 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/2218.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/2218/head:pull/2218

PR: https://git.openjdk.org/jdk11u-dev/pull/2218