Fix JRuby conformance issue by loosening Java's JSONFormatter implementation to be more accepting of DynamicMessage instances of well-known types that have a descriptor with a different object identity but the same full name.

conformance/failure_list_jruby.txt

@@ -144,4 +144,3 @@ Required.Editions_Proto2.ProtobufInput.UnknownOrdering.ProtobufOutput
 Required.Editions_Proto3.ProtobufInput.UnknownOrdering.ProtobufOutput
 Required.Proto2.ProtobufInput.UnknownOrdering.ProtobufOutput
 Required.Proto3.ProtobufInput.UnknownOrdering.ProtobufOutput
-Required.*.JsonInput.AnyWithNoType.JsonOutput # Failed to parse input or produce output.

java/core/src/main/java/com/google/protobuf/AbstractMessage.java

@@ -119,6 +119,17 @@ public int getSerializedSize() {
     return memoizedSize;
   }
 
+  /*
+   * This method will only ever return true if `this` and `other` have the same descriptor instance
+   * for their type (including a gencode message compared to a `DynamicMessage` constructed using
+   * the same descriptor instance).
+   *
+   * For reasons of backward compatibility, a comparison
+   * involving `DynamicMessage` that is constructed using semantically the same descriptor which
+   * was loaded separately (such that the reference identity of the descriptors does not match) will
+   * always return false even if there is otherwise no skew between the descriptors and the contents
+   * of the instances.
+   */
   @Override
   public boolean equals(final Object other) {
     if (other == this) {

java/util/src/main/java/com/google/protobuf/util/JsonFormat.java

@@ -862,7 +862,7 @@ public void print(PrinterImpl printer, MessageOrBuilder message) throws IOExcept
 
     /** Prints google.protobuf.Any */
     private void printAny(MessageOrBuilder message) throws IOException {
-      if (Any.getDefaultInstance().equals(message)) {
+      if (message.getDefaultInstanceForType().equals(message)) {
         generator.print("{}");
         return;
       }