8327799: JFR view: the "Park Until" field of jdk.ThreadPark is invalid if the parking method is not absolute

Reviewed-by: egahlin

src/jdk.jfr/share/classes/jdk/jfr/internal/util/ValueFormatter.java

@@ -343,6 +343,9 @@ public final class ValueFormatter {
     }
 
     public static String formatTimestamp(Instant instant) {
+        if (Instant.MIN.equals(instant)) {
+            return "N/A";
+        }
         return LocalTime.ofInstant(instant, ZoneId.systemDefault()).format(DATE_FORMAT);
     }
 }