Reproduce:
 - make test TEST="vmTestbase/gc/gctests/StringInternGC/StringInternGC.java" JTREG="JOBS=26" CONF=server-release

```
Exception in
gc.gctests.StringInternGC.StringInternGC$StringGenerator@59139e1d
java.lang.OutOfMemoryError: Java heap space
        at java.base/java.util.Arrays.copyOf(Arrays.java:3536)
        at java.base/java.lang.AbstractStringBuilder.ensureCapacityInternal(AbstractStringBuilder.java:228)
        at java.base/java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:802)
        at java.base/java.lang.StringBuffer.append(StringBuffer.java:420)
        at gc.gctests.StringInternGC.StringInternGC$StringGenerator.generateString(StringInternGC.java:57)
        at gc.gctests.StringInternGC.StringInternGC$StringGenerator.run(StringInternGC.java:63)
        at nsk.share.runner.ThreadsRunner$ManagedThread.run(ThreadsRunner.java:106)
        at java.base/java.lang.Thread.run(Thread.java:831)
```