java/util/Collections/CheckedSetBash.java fails with --enable-preview

# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (workspace\open\src\hotspot\share\opto\type.cpp:5119), pid=36052, tid=57656
# assert(!not_flat || !is_flat()) failed: inconsistency
#
# JRE version: Java(TM) SE Runtime Environment (27.0) (fastdebug build 27-jep401ea2-2026-01-25-0655406.chen.l.liang.jdk-6)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 27-jep401ea2-2026-01-25-0655406.chen.l.liang.jdk-6, mixed mode, tiered, compressed oops, compressed class ptrs, g1 gc, windows-amd64)
# Problematic frame:
# V [jvm.dll+0x1184cd3] TypeAryPtr::cast_to_not_flat+0x1e3

Current CompileTask:
C2:7862 1960 4 CheckedSetBash::testCheckedSet (447 bytes)

Stack: [0x000000f396000000,0x000000f396100000], sp=0x000000f3960fb3b0, free space=1004k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [jvm.dll+0x1184cd3] TypeAryPtr::cast_to_not_flat+0x1e3 (type.cpp:5119)
V [jvm.dll+0xee86c3] Parse::Parse+0xa73 (parse1.cpp:653)
V [jvm.dll+0x50d955] ParseGenerator::generate+0xa5 (callGenerator.cpp:100)
V [jvm.dll+0x762742] Parse::do_call+0x892 (doCall.cpp:777)
V [jvm.dll+0xefdbb0] Parse::do_one_bytecode+0x27d0 (parse2.cpp:3598)
V [jvm.dll+0xeed80f] Parse::do_one_block+0x47f (parse1.cpp:1715)
V [jvm.dll+0xeebfae] Parse::do_all_blocks+0x3ce (parse1.cpp:774)
V [jvm.dll+0xee8911] Parse::Parse+0xcc1 (parse1.cpp:678)
V [jvm.dll+0x50d955] ParseGenerator::generate+0xa5 (callGenerator.cpp:100)
V [jvm.dll+0x50f618] PredictedCallGenerator::generate+0x308 (callGenerator.cpp:1045)
[...]

Sometimes there is no hs_err file but one can find the stack trace in the core.html:

Thread 1 (Thread 0xffff6af8f120 (LWP 3752146)):
#0 0x0000ffffa37a27f8 in __pthread_kill_implementation () from /lib64/libc.so.6
#1 0x0000ffffa375ab3c in raise () from /lib64/libc.so.6
#2 0x0000ffffa3747074 in abort () from /lib64/libc.so.6
#3 0x0000ffffa2849ddc in os::abort(bool, void const*, void const*) () from /opt/mach5/mesos/work_dir/jib-master/install/jdk-27-valhalla+1-81/linux-aarch64-debug.jdk/jdk-27/fastdebug/lib/server/libjvm.so
#4 0x0000ffffa2ca27a4 in VMError::report_and_die(int, char const*, char const*, std::__va_list, Thread*, unsigned char*, void const*, void const*, char const*, int, unsigned long) () from /opt/mach5/mesos/work_dir/jib-master/install/jdk-27-valhalla+1-81/linux-aarch64-debug.jdk/jdk-27/fastdebug/lib/server/libjvm.so
#5 0x0000ffffa1d0dec8 in report_vm_error(char const*, int, char const*, char const*, ...) () from /opt/mach5/mesos/work_dir/jib-master/install/jdk-27-valhalla+1-81/linux-aarch64-debug.jdk/jdk-27/fastdebug/lib/server/libjvm.so
#6 0x0000ffffa2be5f7c in TypeAryPtr::cast_to_not_flat(bool) const () from /opt/mach5/mesos/work_dir/jib-master/install/jdk-27-valhalla+1-81/linux-aarch64-debug.jdk/jdk-27/fastdebug/lib/server/libjvm.so
#7 0x0000ffffa288d650 in Parse::Parse(JVMState*, ciMethod*, float) () from /opt/mach5/mesos/work_dir/jib-master/install/jdk-27-valhalla+1-81/linux-aarch64-debug.jdk/jdk-27/fastdebug/lib/server/libjvm.so
#8 0x0000ffffa1a49e8c in ParseGenerator::generate(JVMState*) () from /opt/mach5/mesos/work_dir/jib-master/install/jdk-27-valhalla+1-81/linux-aarch64-debug.jdk/jdk-27/fastdebug/lib/server/libjvm.so
#9 0x0000ffffa1deb414 in Parse::do_call() () from /opt/mach5/mesos/work_dir/jib-master/install/jdk-27-valhalla+1-81/linux-aarch64-debug.jdk/jdk-27/fastdebug/lib/server/libjvm.so
#10 0x0000ffffa28a0060 in Parse::do_one_bytecode() () from /opt/mach5/mesos/work_dir/jib-master/install/jdk-27-valhalla+1-81/linux-aarch64-debug.jdk/jdk-27/fastdebug/lib/server/libjvm.so
#11 0x0000ffffa288883c in Parse::do_one_block() () from /opt/mach5/mesos/work_dir/jib-master/install/jdk-27-valhalla+1-81/linux-aarch64-debug.jdk/jdk-27/fastdebug/lib/server/libjvm.so
#12 0x0000ffffa2889c2c in Parse::do_all_blocks() () from /opt/mach5/mesos/work_dir/jib-master/install/jdk-27-valhalla+1-81/linux-aarch64-debug.jdk/jdk-27/fastdebug/lib/server/libjvm.so
#13 0x0000ffffa288d2d8 in Parse::Parse(JVMState*, ciMethod*, float) () from /opt/mach5/mesos/work_dir/jib-master/install/jdk-27-valhalla+1-81/linux-aarch64-debug.jdk/jdk-27/fastdebug/lib/server/libjvm.so
#14 0x0000ffffa1a49e8c in ParseGenerator::generate(JVMState*) () from /opt/mach5/mesos/work_dir/jib-master/install/jdk-27-valhalla+1-81/linux-aarch64-debug.jdk/jdk-27/fastdebug/lib/server/libjvm.so
#15 0x0000ffffa1a4cb2c in PredictedCallGenerator::generate(JVMState*) () from /opt/mach5/mesos/work_dir/jib-master/install/jdk-27-valhalla+1-81/linux-aarch64-debug.jdk/jdk-27/fastdebug/lib/server/libjvm.so
#16 0x0000ffffa1deb414 in Parse::do_call() () from /opt/mach5/mesos/work_dir/jib-master/install/jdk-27-valhalla+1-81/linux-aarch64-debug.jdk/jdk-27/fastdebug/lib/server/libjvm.so
#17 0x0000ffffa28a0060 in Parse::do_one_bytecode() () from /opt/mach5/mesos/work_dir/jib-master/install/jdk-27-valhalla+1-81/linux-aarch64-debug.jdk/jdk-27/fastdebug/lib/server/libjvm.so