RFR: 8325937: runtime/handshake/HandshakeDirectTest.java causes "monitor end should be strictly below the frame pointer" assertion failure on AArch64 [v4]

[Coleen Phillimore]

> Add missing StoreLoad fences in handshaking code to match safepoint code.  Thanks to @pchilano for finding this bug.
> 
> Tested with tier1-4 and tier8 which has Kitchensink in it.

Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:

  Put suspend handshake fence() where Robbin suggested.

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/21295/files
  - new: https://git.openjdk.org/jdk/pull/21295/files/def6b11a..339cc40a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21295&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21295&range=02-03

  Stats: 8 lines in 1 file changed: 4 ins; 4 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/21295.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21295/head:pull/21295

PR: https://git.openjdk.org/jdk/pull/21295