[11u] RFR 8244287: JFR: Methods samples have line number 0

[Jaroslav Bachorík]

Hi all,

Could I get this simple fix reviewed?
It is fixing a regression introduced while backporting JDK-823790 and
adding a new test to prevent such regressions in the future.

JIRA      :  https://bugs.openjdk.java.net/browse/JDK-8244287
Webrev : http://cr.openjdk.java.net/~jbachorik/8244287/webrev/

Thanks,

-JB-