Arguments which are passed to -XX:StartFlightRecording are not shown in spite of -Xlog:jfr+dcmd=debug is passed.

jfr.dcmd log will be shown from DCmdStart::execute, but I think it has two problems:

  1. Log level will be not set before showing log.
     LogTag::tagSetLevel is used to decide to show the log. But it will be set
     in JNI code which is called by JVM::<clinit>. JVM class is not loaded
     when DCmdStart::execute tries to show log.

  2. `settings` might be null, so NPE will occur when DCmdStart::execute
      tries to show log.