Enable helpful null pointer exceptions (#54853)

Now that JDK 14 is available, and we are bundling it, this commit
enables us to run with helpful null pointer exceptions, which will be a
great aid in debugging.

distribution/tools/launchers/src/main/java/org/elasticsearch/tools/launchers/SystemJvmOptions.java

@@ -55,6 +55,8 @@ static List<String> systemJvmOptions() {
                  * debugging.
                  */
                 "-XX:-OmitStackTraceInFastThrow",
+                // enable helpful NullPointerExceptions (https://openjdk.java.net/jeps/358), if they are supported
+                maybeShowCodeDetailsInExceptionMessages(),
                 // flags to configure Netty
                 "-Dio.netty.noUnsafe=true",
                 "-Dio.netty.noKeySetOptimization=true",
@@ -69,6 +71,14 @@ static List<String> systemJvmOptions() {
         );
     }
 
+    private static String maybeShowCodeDetailsInExceptionMessages() {
+        if (JavaVersion.majorVersion(JavaVersion.CURRENT) >= 14) {
+            return "-XX:+ShowCodeDetailsInExceptionMessages";
+        } else {
+            return "";
+        }
+    }
+
     private static String javaLocaleProviders() {
         /**
          *  SPI setting is used to allow loading custom CalendarDataProvider