Hang in SanityTest

[hzongaro]

Recent PR builds have encountered a test case timeout in SanityTest on RISC-V. From https://ci.eclipse.org/omr/job/PullRequest-linux_riscv64_cross/1367 for example:

09:31:32  21: omrthread_attr_set_priority(&attr, 12) failed: retVal 15 (f)
09:31:32  21: [----------] 15 tests from ThreadCreateTest (33 ms total)
09:31:32  21: 
09:31:32  21: [----------] 8 tests from JoinTest
09:31:37  21: [----------] 8 tests from JoinTest (6016 ms total)
09:31:37  21: 
09:31:37  21: [----------] 1 test from KeyDestructorTest
09:31:37  21: [----------] 1 test from KeyDestructorTest (3 ms total)
09:31:37  21: 
09:31:37  21: [----------] 5 tests from LockedMonitorCountTest
09:31:37  21: [----------] 5 tests from LockedMonitorCountTest (5 ms total)
09:31:37  21: 
09:31:37  21: [----------] 7 tests from SanityTest
11:13:25  Cancelling nested steps due to timeout
11:13:25  Sending interrupt signal to process
11:13:30  Terminated
11:13:31  script returned exit code 143