compiler/graalunit/ReplacementsTest.java fails due to EXCEPTION_ACCESS_VIOLATION

The following test failure was spotted in the JDK14 CI:

compiler/graalunit/ReplacementsTest.java

Here's a snippet from the log file:

org.graalvm.compiler.replacements.test.WordTest started (55 of 56)
  construction: #
# A fatal error has been detected by the Java Runtime Environment:
#
# EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x00007ffa38bbf165, pid=13496, tid=17908
#
# JRE version: Java(TM) SE Runtime Environment (14.0+6) (fastdebug build 14-ea+6-139)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 14-ea+6-139, mixed mode, sharing, tiered, jvmci, compressed oops, g1 gc, windows-amd64)
# Problematic frame:
# V [jvm.dll+0xa9f165] nmethod::is_unloading+0x65
#
# Core dump will be written. Default location: T:\\testoutput\\test-support\\jtreg_open_test_hotspot_jtreg_compiler_graalunit\\scratch\\4\\hs_err_pid13496.mdmp
#
# An error report file with more information is saved as:
# T:\\testoutput\\test-support\\jtreg_open_test_hotspot_jtreg_compiler_graalunit\\scratch\\4\\hs_err_pid13496.log
Compiled method (JVMCI) 128979 18567 4 (method)
 total in heap [0x0000007e2b512a90,0x0000007e2b512f30] = 1184
 relocation [0x0000007e2b512c08,0x0000007e2b512c30] = 40
 main code [0x0000007e2b512c40,0x0000007e2b512e40] = 512
 stub code [0x0000007e2b512e40,0x0000007e2b512e50] = 16
 oops [0x0000007e2b512e50,0x0000007e2b512e70] = 32
 metadata [0x0000007e2b512e70,0x0000007e2b512e90] = 32
 scopes data [0x0000007e2b512e90,0x0000007e2b512eb8] = 40
 scopes pcs [0x0000007e2b512eb8,0x0000007e2b512f08] = 80
 dependencies [0x0000007e2b512f08,0x0000007e2b512f10] = 8
 nul chk table [0x0000007e2b512f10,0x0000007e2b512f20] = 16
 JVMCI data [0x0000007e2b512f20,0x0000007e2b512f30] = 16
Compiled method (JVMCI) 128979 18569 4 (method)
 total in heap [0x0000007e2b512f90,0x0000007e2b5135c8] = 1592
 relocation [0x0000007e2b513108,0x0000007e2b513128] = 32
 main code [0x0000007e2b513140,0x0000007e2b5134fc] = 956
 stub code [0x0000007e2b5134fc,0x0000007e2b513500] = 4
 oops [0x0000007e2b513500,0x0000007e2b513520] = 32
 metadata [0x0000007e2b513520,0x0000007e2b513538] = 24
 scopes data [0x0000007e2b513538,0x0000007e2b513548] = 16
 scopes pcs [0x0000007e2b513548,0x0000007e2b513598] = 80
 dependencies [0x0000007e2b513598,0x0000007e2b5135a0] = 8
 nul chk table [0x0000007e2b5135a0,0x0000007e2b5135b8] = 24
 JVMCI data [0x0000007e2b5135b8,0x0000007e2b5135c8] = 16
Compiled method (JVMCI) 128979 18569 4 (method)
 total in heap [0x0000007e2b512f90,0x0000007e2b5135c8] = 1592
 relocation [0x0000007e2b513108,0x0000007e2b513128] = 32
 main code [0x0000007e2b513140,0x0000007e2b5134fc] = 956
 stub code [0x0000007e2b5134fc,0x0000007e2b513500] = 4
 oops [0x0000007e2b513500,0x0000007e2b513520] = 32
 metadata [0x0000007e2b513520,0x0000007e2b513538] = 24
 scopes data [0x0000007e2b513538,0x0000007e2b513548] = 16
 scopes pcs [0x0000007e2b513548,0x0000007e2b513598] = 80
 dependencies [0x0000007e2b513598,0x0000007e2b5135a0] = 8
 nul chk table [0x0000007e2b5135a0,0x0000007e2b5135b8] = 24
 JVMCI data [0x0000007e2b5135b8,0x0000007e2b5135c8] = 16
Compiled method (JVMCI) 128984 18569 4 (method)
 total in heap [0x0000007e2b512f90,0x0000007e2b5135c8] = 1592
 relocation [0x0000007e2b513108,0x0000007e2b513128] = 32
 main code [0x0000007e2b513140,0x0000007e2b5134fc] = 956
 stub code [0x0000007e2b5134fc,0x0000007e2b513500] = 4
 oops [0x0000007e2b513500,0x0000007e2b513520] = 32
 metadata [0x0000007e2b513520,0x0000007e2b513538] = 24
 scopes data [0x0000007e2b513538,0x0000007e2b513548] = 16
 scopes pcs [0x0000007e2b513548,0x0000007e2b513598] = 80
 dependencies [0x0000007e2b513598,0x0000007e2b5135a0] = 8
 nul chk table [0x0000007e2b5135a0,0x0000007e2b5135b8] = 24
 JVMCI data [0x0000007e2b5135b8,0x0000007e2b5135c8] = 16
Compiled method (JVMCI) 128986 18569 4 (method)
 total in heap [0x0000007e2b512f90,0x0000007e2b5135c8] = 1592
 relocation [0x0000007e2b513108,0x0000007e2b513128] = 32
 main code [0x0000007e2b513140,0x0000007e2b5134fc] = 956
 stub code [0x0000007e2b5134fc,0x0000007e2b513500] = 4
 oops [0x0000007e2b513500,0x0000007e2b513520] = 32
 metadata [0x0000007e2b513520,0x0000007e2b513538] = 24
 scopes data [0x0000007e2b513538,0x0000007e2b513548] = 16
 scopes pcs [0x0000007e2b513548,0x0000007e2b513598] = 80
 dependencies [0x0000007e2b513598,0x0000007e2b5135a0] = 8
 nul chk table [0x0000007e2b5135a0,0x0000007e2b5135b8] = 24
 JVMCI data [0x0000007e2b5135b8,0x0000007e2b5135c8] = 16
#
# If you would like to submit a bug report, please visit:
# http://bugreport.java.com/bugreport/crash.jsp
#

Some similar stack traces, also some found with HotspotTest:
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [jvm.dll+0xa9df15] nmethod::is_unloading+0x65 (nmethod.cpp:1744)
V [jvm.dll+0xc2a08a] NMethodSweeper::process_compiled_method+0xca (sweeper.cpp:673)
V [jvm.dll+0xc2a8a9] NMethodSweeper::sweep_code_cache+0x399 (sweeper.cpp:545)
V [jvm.dll+0xc29a98] NMethodSweeper::possibly_sweep+0x308 (sweeper.cpp:463)
V [jvm.dll+0xc2b095] NMethodSweeper::sweeper_loop+0x225 (sweeper.cpp:351)
V [jvm.dll+0xc88684] JavaThread::run+0x2d4 (thread.cpp:1934)
V [jvm.dll+0xc7e2e2] Thread::call_run+0x192 (thread.cpp:405)
V [jvm.dll+0xadb50e] thread_native_entry+0x10e (os_windows.cpp:471)
C [ucrtbase.DLL+0x203ba]
C [KERNEL32.DLL+0x13f2]
C [ntdll.dll+0x154f4]

Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [jvm.dll+0x43c357] DependencyContext::dependencies_not_unloading+0x27 (dependencycontext.cpp:286)
V [jvm.dll+0x43c5af] DependencyContext::mark_dependent_nmethods+0x1f (dependencycontext.cpp:68)
V [jvm.dll+0x5c5991] InstanceKlass::mark_dependent_nmethods+0x61 (instanceklass.cpp:2185)
V [jvm.dll+0x3beef3] CodeCache::flush_dependents_on+0x153 (codecache.cpp:1200)
V [jvm.dll+0xb434e7] SystemDictionary::define_instance_class+0x2e7 (systemdictionary.cpp:1589)
V [jvm.dll+0xb4559c] SystemDictionary::find_or_define_instance_class+0x2fc (systemdictionary.cpp:1683)
V [jvm.dll+0xb4882c] SystemDictionary::resolve_from_stream+0x2bc (systemdictionary.cpp:1128)
V [jvm.dll+0x6b6ba2] jvm_define_class_common+0x252 (jvm.cpp:974)
V [jvm.dll+0x6c09c3] JVM_DefineClassWithSource+0x203 (jvm.cpp:998)
C [java.dll+0x1b76]

Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0xa34409] DependencyContext::add_dependent_nmethod(nmethod*)+0x99
V [libjvm.so+0xd3fa61] InstanceKlass::add_dependent_nmethod(nmethod*)+0x71
V [libjvm.so+0x1324ab2] nmethod::new_nmethod(methodHandle const&, int, int, CodeOffsets*, int, DebugInformationRecorder*, Dependencies*, CodeBuffer*, int, OopMapSet*, ExceptionHandlerTable*, ImplicitExceptionTable*, AbstractCompiler*, int, char*, int, int, char const*, FailedSpeculation**)+0x362
V [libjvm.so+0x889be2] ciEnv::register_method(ciMethod*, int, CodeOffsets*, int, CodeBuffer*, int, OopMapSet*, ExceptionHandlerTable*, ImplicitExceptionTable*, AbstractCompiler*, bool, bool, RTMState)+0x312
V [libjvm.so+0x708c38] Compilation::install_code(int)+0xd8
V [libjvm.so+0x70bdcb] Compilation::compile_method()+0x5eb
V [libjvm.so+0x70c38a] Compilation::Compilation(AbstractCompiler*, ciEnv*, ciMethod*, int, BufferBlob*, DirectiveSet*)+0x33a
V [libjvm.so+0x70d0fe] Compiler::compile_method(ciEnv*, ciMethod*, int, DirectiveSet*)+0x14e
V [libjvm.so+0x9a810c] CompileBroker::invoke_compiler_on_method(CompileTask*)+0x2cc
V [libjvm.so+0x9a90b8] CompileBroker::compiler_thread_loop()+0x468
V [libjvm.so+0x1670726] JavaThread::thread_main_inner()+0x226
V [libjvm.so+0x1675e06] Thread::call_run()+0xf6
V [libjvm.so+0x13a7fce] thread_native_entry(Thread*)+0x10e

Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0x586725] DependencyContext::remove_dependent_nmethod(nmethod*)+0x125
V [libjvm.so+0x74d3b1] InstanceKlass::remove_dependent_nmethod(nmethod*)+0x31
V [libjvm.so+0xb08da9] nmethod::flush_dependencies(bool) [clone .part.0]+0x69
V [libjvm.so+0xb09408] nmethod::make_not_entrant_or_zombie(int) [clone .part.0]+0x3d8
V [libjvm.so+0xc8a3f3] NMethodSweeper::process_compiled_method(CompiledMethod*)+0x83
V [libjvm.so+0xc8a974] NMethodSweeper::sweep_code_cache()+0x1f4
V [libjvm.so+0xc8b05c] NMethodSweeper::sweep()+0x5c
V [libjvm.so+0xc8b433] NMethodSweeper::sweeper_loop()+0xf3
V [libjvm.so+0xcf0d1e] JavaThread::thread_main_inner()+0xde
V [libjvm.so+0xcf5b8d] Thread::call_run()+0xfd
V [libjvm.so+0xb48907] thread_native_entry(Thread*)+0xe7

Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.dylib+0x5a0077] nmethodBucket::next_not_unloading()+0x47
V [libjvm.dylib+0x5a0353] DependencyContext::remove_dependent_nmethod(nmethod*)+0x83
V [libjvm.dylib+0x7f6d43] InstanceKlass::remove_dependent_nmethod(nmethod*)+0x73
V [libjvm.dylib+0xd87062] nmethod::flush_dependencies(bool)+0x212
V [libjvm.dylib+0xd877b8] nmethod::make_not_entrant_or_zombie(int)+0x498
V [libjvm.dylib+0xfa74bd] NMethodSweeper::process_compiled_method(CompiledMethod*)+0x13d
V [libjvm.dylib+0xfa6d3b] NMethodSweeper::sweep_code_cache()+0x29b
V [libjvm.dylib+0xfa65fe] NMethodSweeper::sweep()+0x1be
V [libjvm.dylib+0xfa62d5] NMethodSweeper::sweeper_loop()+0x25
V [libjvm.dylib+0x10205e3] JavaThread::thread_main_inner()+0x2a3
V [libjvm.dylib+0x101b837] Thread::call_run()+0x1b7
V [libjvm.dylib+0xddc76f] thread_native_entry(Thread*)+0x15f
C [libsystem_pthread.dylib+0x3661] _pthread_body+0x154
C [libsystem_pthread.dylib+0x350d] _pthread_body+0x0
C [libsystem_pthread.dylib+0x2bf9] thread_start+0xd