[jdk17u-dev] RFR: 8325937: runtime/handshake/HandshakeDirectTest.java causes "monitor end should be strictly below the frame pointer" assertion failure on AArch64

[Goetz Lindenmaier]

I backport this for parity with 17.0.15-oracle.


It does not apply as 
8292591: Experimentally add back barrier-less Java thread transitions
is not in 17. 

Resolving this is obvious, the flag tested in the context in 21 is "false" by default.
Thus adding the code unconditional is the obvious thing to do.

I added one comment from 8292591 in execute().  This change duplicates this comment in doit(),
so it's canonical to have it in execute(), too.

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Commit messages:
 - Backport 83e9e482b181e76ca9f645e8cc83cfa9337df498

Changes: https://git.openjdk.org/jdk17u-dev/pull/3140/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=3140&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8325937
  Stats: 13 lines in 1 file changed: 12 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/3140.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/3140/head:pull/3140

PR: https://git.openjdk.org/jdk17u-dev/pull/3140