RFR: 8218202: gc/stress/TestStressG1Humongous.java to ProblemList-graal.txt

[Kim Barrett]

Please review this addition to ProblemList-graal.txt.  See comment in main bug for details:
https://bugs.openjdk.java.net/browse/JDK-8218176?focusedCommentId=14242017&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14242017

CR:
https://bugs.openjdk.java.net/browse/JDK-8218202

Main Bug:
https://bugs.openjdk.java.net/browse/JDK-8218176

Webrev:
http://cr.openjdk.java.net/~kbarrett/8218202/open.00/

Testing:
Locally verified exclusion of test when using ProblemList-graal.txt