8215534: [testbug] some jfr test don't check @requires vm.hasJFR

[Lindenmaier, Goetz]

Hi,

These tests lack @requires vm.hasJFR, thus they are failing on AIX.
http://cr.openjdk.java.net/~goetz/wr18/8215334-JFR_requires/01/

Please review.
I will push this to jdk12 as it is a testbug if I miss  the RDP deadline.

Best regards,
  Goetz.