ARM32 Zero: atomic_copy64 is incorrect, breaking volatile stores

Running current arm32-zero binaries with jcstress yields this exception:

$ java -jar jcstress-tests-all-20200917.jar --jvmArgs "-Xint" -m quick
Java Concurrency Stress Tests
---------------------------------------------------------------------------------
Rev: ad66703e2ed0, built by buildbot with 11.0.5-testing at 2020-09-17T13:24:16Z

Exception in thread "main" java.util.ServiceConfigurationError: Locale provider adapter "CLDR"cannot be instantiated.
at java.base/sun.util.locale.provider.LocaleProviderAdapter.forType(LocaleProviderAdapter.java:199)
at java.base/sun.util.locale.provider.LocaleProviderAdapter.findAdapter(LocaleProviderAdapter.java:287)
at java.base/sun.util.locale.provider.LocaleProviderAdapter.getAdapter(LocaleProviderAdapter.java:258)
at java.base/java.util.Calendar.createCalendar(Calendar.java:1693)
at java.base/java.util.Calendar.getInstance(Calendar.java:1661)
at java.base/java.text.SimpleDateFormat.initializeCalendar(SimpleDateFormat.java:677)
at java.base/java.text.SimpleDateFormat.<init>(SimpleDateFormat.java:621)
at org.openjdk.jcstress.Options.parse(Options.java:176)
at org.openjdk.jcstress.Main.main(Main.java:48)
Caused by: java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:64)
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500)
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:481)
at java.base/sun.util.locale.provider.LocaleProviderAdapter.forType(LocaleProviderAdapter.java:188)
... 8 more
Caused by: java.lang.OutOfMemoryError: Cannot reserve 8192 bytes of direct buffer memory (allocated: 0, limit: -5290888278393214624)
at java.base/java.nio.Bits.reserveMemory(Bits.java:178)
at java.base/java.nio.DirectByteBuffer.<init>(DirectByteBuffer.java:120)
at java.base/java.nio.ByteBuffer.allocateDirect(ByteBuffer.java:330)
at java.base/jdk.internal.jimage.ImageBufferCache.allocateBuffer(ImageBufferCache.java:52)
at java.base/jdk.internal.jimage.ImageBufferCache.getBuffer(ImageBufferCache.java:85)
at java.base/jdk.internal.jimage.BasicImageReader.readBuffer(BasicImageReader.java:364)
at java.base/jdk.internal.jimage.BasicImageReader.getResourceBuffer(BasicImageReader.java:421)
at java.base/jdk.internal.jimage.ImageReader.getResourceBuffer(ImageReader.java:194)
at java.base/jdk.internal.module.SystemModuleFinders$SystemModuleReader.read(SystemModuleFinders.java:466)
at java.base/jdk.internal.loader.BuiltinClassLoader.defineClass(BuiltinClassLoader.java:802)
at java.base/jdk.internal.loader.BuiltinClassLoader.findClassInModuleOrNull(BuiltinClassLoader.java:735)
at java.base/jdk.internal.loader.BuiltinClassLoader.findClass(BuiltinClassLoader.java:616)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:634)
at java.base/java.lang.Class.forName(Class.java:546)
at java.base/java.util.ServiceLoader.loadProvider(ServiceLoader.java:854)
at java.base/java.util.ServiceLoader$ModuleServicesLookupIterator.hasNext(ServiceLoader.java:1078)
at java.base/java.util.ServiceLoader$2.hasNext(ServiceLoader.java:1301)
at java.base/java.util.ServiceLoader$3.hasNext(ServiceLoader.java:1386)
at java.base/sun.util.cldr.CLDRLocaleProviderAdapter$1.run(CLDRLocaleProviderAdapter.java:89)
at java.base/sun.util.cldr.CLDRLocaleProviderAdapter$1.run(CLDRLocaleProviderAdapter.java:86)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:554)
at java.base/sun.util.cldr.CLDRLocaleProviderAdapter.<init>(CLDRLocaleProviderAdapter.java:86)
... 14 more

This seems to only happen with release builds. fastdebug builds seem to pass fine.

Bisection points to JDK-8218565, and its reversal makes the release builds work. But that makes little sense! It must be just triggering the other bug, not being the root cause itself.