Add support for MethodHandles.classData

Add support for build-time- and run-time-loaded classes.

Author: gilles-duboscq

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/DynamicHub.java

@@ -150,6 +150,7 @@
 import jdk.graal.compiler.nodes.java.FinalFieldBarrierNode;
 import jdk.graal.compiler.replacements.ReplacementsUtil;
 import jdk.internal.access.JavaLangReflectAccess;
+import jdk.internal.access.SharedSecrets;
 import jdk.internal.misc.Unsafe;
 import jdk.internal.reflect.CallerSensitive;
 import jdk.internal.reflect.CallerSensitiveAdapter;
@@ -452,8 +453,9 @@ public DynamicHub(Class<?> hostedJavaClass, String name, byte hubType, Reference
         this.flags = flags;
 
         Object loader = PredefinedClassesSupport.isPredefined(hostedJavaClass) ? NO_CLASS_LOADER : classLoader;
+        Object classData = SharedSecrets.getJavaLangAccess().classData(hostedJavaClass);
         this.companion = DynamicHubCompanion.createHosted(hostedJavaClass.getModule(), superType, sourceFileName,
-                        modifiers, loader, nestHost, simpleBinaryName, declaringClass, signature);
+                        modifiers, loader, nestHost, simpleBinaryName, declaringClass, signature, classData);
     }
 
     /**
@@ -2328,6 +2330,11 @@ private Class<?>[] getPermittedSubclasses0() {
     @KeepOriginal
     native boolean casAnnotationType(AnnotationType oldType, AnnotationType newType);
 
+    @Substitute
+    Object getClassData() {
+        return companion.classData;
+    }
+
     /*
      * We need to filter out hiding and negative elements at the last moment. This ensures that the
      * JDK internals see them as regular methods and fields and ensure their visibility is correct,

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/DynamicHubCompanion.java

@@ -153,22 +153,22 @@ public final class DynamicHubCompanion {
     Constructor<?> cachedConstructor;
     Object jfrEventConfiguration;
     @Stable boolean canUnsafeAllocate;
+    Object classData;
 
     @Platforms(Platform.HOSTED_ONLY.class)
     static DynamicHubCompanion createHosted(Module module, DynamicHub superHub, String sourceFileName, int modifiers,
-                    Object classLoader, Class<?> nestHost, String simpleBinaryName, Object declaringClass, String signature) {
-
-        return new DynamicHubCompanion(module, superHub, sourceFileName, modifiers, classLoader, nestHost, simpleBinaryName, declaringClass, signature);
+                    Object classLoader, Class<?> nestHost, String simpleBinaryName, Object declaringClass, String signature, Object classData) {
+        return new DynamicHubCompanion(module, superHub, sourceFileName, modifiers, classLoader, nestHost, simpleBinaryName, declaringClass, signature, classData);
     }
 
     static DynamicHubCompanion createAtRuntime(Module module, DynamicHub superHub, String sourceFileName, int modifiers,
                     ClassLoader classLoader, String simpleBinaryName, Object declaringClass, String signature, ClassDefinitionInfo info) {
         assert RuntimeClassLoading.isSupported();
-        return new DynamicHubCompanion(module, superHub, sourceFileName, modifiers, classLoader, info.dynamicNest, simpleBinaryName, declaringClass, signature);
+        return new DynamicHubCompanion(module, superHub, sourceFileName, modifiers, classLoader, info.dynamicNest, simpleBinaryName, declaringClass, signature, info.classData);
     }
 
     private DynamicHubCompanion(Module module, DynamicHub superHub, String sourceFileName, int modifiers,
-                    Object classLoader, Class<?> nestHost, String simpleBinaryName, Object declaringClass, String signature) {
+                    Object classLoader, Class<?> nestHost, String simpleBinaryName, Object declaringClass, String signature, Object classData) {
         this.module = module;
         this.superHub = superHub;
         this.sourceFileName = sourceFileName;
@@ -179,6 +179,7 @@ private DynamicHubCompanion(Module module, DynamicHub superHub, String sourceFil
         this.signature = signature;
 
         this.classLoader = classLoader;
+        this.classData = classData;
     }
 
     public void setHubMetadata(RuntimeDynamicHubMetadata hubMetadata) {