Output handle information to native handle error message.

Author: aardvark179

src/main/java/org/truffleruby/cext/CExtNodes.java

@@ -1322,12 +1322,17 @@ public Object unwrap(Object value,
             Object object = unwrapNode.execute(value);
             if (object == null) {
                 exceptionProfile.enter();
-                throw new RaiseException(getContext(), coreExceptions().runtimeError("native handle not found", this));
+                throw new RaiseException(getContext(), coreExceptions().runtimeError(exceptionMessage(value), this));
             } else {
                 return object;
             }
         }
 
+        @TruffleBoundary
+        private String exceptionMessage(Object value) {
+            return String.format("native handle not found (%s)", value);
+        }
+
         protected UnwrapNode createUnwrapNode() {
             return UnwrapNodeGen.create();
         }