Disable current thread workaround for JDK 20.

Author: peter-hofer

substratevm/src/com.oracle.svm.agent/src/com/oracle/svm/agent/BreakpointInterceptor.java

@@ -217,7 +217,7 @@ private static boolean forName(JNIEnvironment jni, JNIObjectHandle thread, Break
         boolean classLoaderValid = true;
         WordPointer classLoaderPtr = StackValue.get(WordPointer.class);
         if (bp.method == agent.handles().javaLangClassForName3) {
-            assert thread.notEqual(nullHandle()) : "JDK-8292657: must not use NULL for the current thread because it does not apply to virtual threads on JDK 19";
+            assert thread.notEqual(nullHandle()) || Support.jvmtiVersion() != JvmtiInterface.JVMTI_VERSION_19 : "JDK-8292657";
             classLoaderValid = (jvmtiFunctions().GetLocalObject().invoke(jvmtiEnv(), thread, 0, 2, classLoaderPtr) == JvmtiError.JVMTI_ERROR_NONE);
         } else {
             classLoaderPtr.write(nullHandle());
@@ -1288,15 +1288,15 @@ private static void onBreakpoint(@SuppressWarnings("unused") JvmtiEnv jvmti, JNI
      * used to properly read the locals in the breakpoint.
      */
     private static JNIObjectHandle rectifyCurrentThread(JNIObjectHandle thread) {
-        if (Support.jvmtiVersion() < JvmtiInterface.JVMTI_VERSION_19) {
+        if (Support.jvmtiVersion() != JvmtiInterface.JVMTI_VERSION_19) {
             return thread;
         }
+
         WordPointer threadPtr = StackValue.get(WordPointer.class);
         JvmtiError error = jvmtiFunctions().GetCurrentThread().invoke(jvmtiEnv(), threadPtr);
         if (error == JvmtiError.JVMTI_ERROR_WRONG_PHASE) {
             return nullHandle();
         }
-
         check(error);
         return threadPtr.read();
     }

substratevm/src/com.oracle.svm.jvmtiagentbase/src/com/oracle/svm/jvmtiagentbase/Support.java

@@ -185,7 +185,7 @@ public static JNIMethodId getCallerMethod(int depth) {
     }
 
     public static JNIObjectHandle getObjectArgument(JNIObjectHandle thread, int slot) {
-        assert thread.notEqual(nullHandle()) : "JDK-8292657: must not use NULL for the current thread because it does not apply to virtual threads on JDK 19";
+        assert thread.notEqual(nullHandle()) || jvmtiVersion() != JvmtiInterface.JVMTI_VERSION_19 : "JDK-8292657";
         WordPointer handlePtr = StackValue.get(WordPointer.class);
         if (jvmtiFunctions().GetLocalObject().invoke(jvmtiEnv(), thread, 0, slot, handlePtr) != JvmtiError.JVMTI_ERROR_NONE) {
             return nullHandle();
@@ -198,7 +198,7 @@ public static JNIObjectHandle getObjectArgument(JNIObjectHandle thread, int slot
      * for instance methods, not static methods.
      */
     public static JNIObjectHandle getReceiver(JNIObjectHandle thread) {
-        assert thread.notEqual(nullHandle()) : "JDK-8292657: must not use NULL for the current thread because it does not apply to virtual threads on JDK 19";
+        assert thread.notEqual(nullHandle()) || jvmtiVersion() != JvmtiInterface.JVMTI_VERSION_19 : "JDK-8292657";
         WordPointer handlePtr = StackValue.get(WordPointer.class);
         JvmtiError result = jvmtiFunctions().GetLocalInstance().invoke(jvmtiEnv(), thread, 0, handlePtr);
         if (result != JvmtiError.JVMTI_ERROR_NONE) {