RFR (XXS) 8215314: [Graal] Enable org.graalvm.compiler.core.test.CountedLoopTest

[Ekaterina Pavlova]

Hi,

JDK-8211179 "[Graal] org.graalvm.compiler.core.test.CountedLoopTest fails with NullPointerException" has been fixed.
Please review tiny change in test/hotspot/jtreg/ProblemList-graal.txt which returns
org.graalvm.compiler.core.test.CountedLoopTest back to the testing.


     JBS: https://bugs.openjdk.java.net/browse/JDK-8215314
  webrev: http://cr.openjdk.java.net/~epavlova//8215314/webrev.00/
testing: tested by running graalunit tests

thanks,
-katya