Ensure the class name is valid when enhancing though SerialVersionUIDAdder

Author: amarziali

dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/context/asm/SerialVersionUIDAdder.java

@@ -182,7 +182,7 @@ public void visit(
       final String[] interfaces) {
     // Get the class name, access flags, and interfaces information (step 1, 2 and 3) for SVUID
     // computation.
-    computeSvuid = (access & Opcodes.ACC_ENUM) == 0;
+    computeSvuid = name != null && (access & Opcodes.ACC_ENUM) == 0;
 
     if (computeSvuid) {
       this.name = name;