[11u] gc/stress/gcold/TestGCOldWithZ failing with OOM

In SAP's CI, the test compiler/gcbarriers/UnsafeIntrinsicsTest_z is constantly failing with OOMs in a certain linux configuration:

----------messages:(4/328)----------
command: main -Xmx256m -XX:+UnlockExperimentalVMOptions -XX:+UseZGC gc.stress.gcold.TestGCOldWithZ 50 5 20 1 5000
reason: User specified action: run main/othervm -Xmx256m -XX:+UnlockExperimentalVMOptions -XX:+UseZGC gc.stress.gcold.TestGCOldWithZ 50 5 20 1 5000
Mode: othervm [/othervm specified]
elapsed time (seconds): 1.389
----------configuration:(0/0)----------
----------System.out:(7/279)----------
For random generator using seed: 1171441089055025957
To re-run test with same seed value please add "-Djdk.test.lib.random.seed=1171441089055025957" to command line.
50 megabytes of live storage
5 work units per step
promotion ratio is 1:20
pointer mutation rate is 1
5000 steps
----------System.err:(8/286)----------
Allocating 152 trees.
  (49804320 bytes)
  (2490216 nodes)
Initialization complete...

Exception: java.lang.OutOfMemoryError thrown from the UncaughtExceptionHandler in thread "MainThread"

Exception: java.lang.OutOfMemoryError thrown from the UncaughtExceptionHandler in thread "main"