Multiple JFR tests have started failing

The failures all involve a SEGV in Unsafe.putInt but I suspect that is a deliberate crash as part of the test. But then JFR is not finding any recording and the tests are all failing:

jdk/jfr/event/runtime/TestDumpReason.java
jdk/jfr/event/runtime/TestShutdownEvent.java
jdk/jfr/jvm/TestDumpOnCrash.java

Happens on all platforms - total of 13 failures per tier 5 run.

Sample failure mode:

========== Crasher process output:
#
# A fatal error has been detected by the Java Runtime Environment:
#
# EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x00007ffd760617fd, pid=5036, tid=6788
#
# JRE version: Java(TM) SE Runtime Environment (22.0+26) (fastdebug build 22-ea+26-2104)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 22-ea+26-2104, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, windows-amd64)
# Problematic frame:
# V [jvm.dll+0xed17fd] Unsafe_PutInt+0x1bd
#
# CreateCoredumpOnCrash turned off, no core file dumped
#
# JFR recording file will be written. Location: C:\\sb\\prod\\1701311208\\testoutput\\test-support\\jtreg_open_test_jdk_jdk_jfr\\scratch\\1\\hs_err_pid5036.jfr
#
# An error report file with more information is saved as:
# C:\\sb\\prod\\1701311208\\testoutput\\test-support\\jtreg_open_test_jdk_jdk_jfr\\scratch\\1\\hs_err_pid5036.log
[2.401s][warning][os] Loading hsdis library failed
 (no locks)
[error occurred during error reporting (), id 0xe0000000, Internal Error (c:\\sb\\prod\\1701266984\\workspace\\open\\src\\hotspot\\share\\runtime\\javaThread.cpp:363)]
#
# If you would like to submit a bug report, please visit:
# https://bugreport.java.com/bugreport/crash.jsp
#

==================================
Attempt 0. Verification failed:
File length 0. Should at least be some bytes: expected 0 to not equal 0
Retrying...