This failure was observed in one of the CI runs:

    java.lang.IllegalArgumentException: hash must be nonzero
        at java.base/jdk.internal.classfile.impl.EntryMap.firstToken(EntryMap.java:84)
        at java.base/jdk.internal.classfile.impl.SplitConstantPool.tryFindUtf8(SplitConstantPool.java:330)
        at java.base/jdk.internal.classfile.impl.SplitConstantPool.utf8Entry(SplitConstantPool.java:365)
        at java.base/jdk.internal.classfile.impl.SplitConstantPool.utf8Entry(SplitConstantPool.java:59)
        at java.base/java.lang.classfile.constantpool.ConstantPoolBuilder.classEntry(ConstantPoolBuilder.java:153)
        at java.base/java.lang.classfile.ClassFile.build(ClassFile.java:332)
        at java.base/java.lang.invoke.ClassSpecializer$Factory.generateConcreteSpeciesCodeFile(ClassSpecializer.java:620)
        at java.base/java.lang.invoke.ClassSpecializer$Factory.generateConcreteSpeciesCode(ClassSpecializer.java:581)
        at java.base/java.lang.invoke.ClassSpecializer$Factory.loadSpecies(ClassSpecializer.java:501)
        at java.base/java.lang.invoke.ClassSpecializer.findSpecies(ClassSpecializer.java:205)
        at java.base/java.lang.invoke.BoundMethodHandle$SpeciesData.extendWith(BoundMethodHandle.java:360)
        at java.base/java.lang.invoke.LambdaFormEditor.newSpeciesData(LambdaFormEditor.java:516)
        at java.base/java.lang.invoke.LambdaFormEditor.bindArgumentForm(LambdaFormEditor.java:579)
        at java.base/java.lang.invoke.LambdaFormEditor.bindArgumentL(LambdaFormEditor.java:523)
        at java.base/java.lang.invoke.BoundMethodHandle.bindArgumentL(BoundMethodHandle.java:72)
        at java.base/java.lang.invoke.MethodHandles.insertArguments(MethodHandles.java:5263)
        at TestMethods$6.getMH(TestMethods.java:244)
        at TestMethods.getTestCaseMH(TestMethods.java:561)
        at LFSingleThreadCachingTest.doTest(LFSingleThreadCachingTest.java:67)
        at jdk.test.lib.Utils.filterException(Utils.java:641)
        at test.java.lang.invoke.lib.CodeCacheOverflowProcessor.runMHTest(CodeCacheOverflowProcessor.java:71)
        at LambdaFormTestCase$TestRun.doIteration(LambdaFormTestCase.java:127)
        at jdk.test.lib.TimeLimitedRunner.call(TimeLimitedRunner.java:71)
        at LambdaFormTestCase.runTests(LambdaFormTestCase.java:188)
        at LFSingleThreadCachingTest.main(LFSingleThreadCachingTest.java:81)
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
        at java.base/java.lang.reflect.Method.invoke(Method.java:580)
        at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
        at java.base/java.lang.Thread.run(Thread.java:1575)
FAILED. Caused by hash must be nonzero