Test java/util/Base64/TestEncodingDecodingLength.java fails with OOME using ParallelGC after JDK-8330670

After JDK-8330670 was integrated this test started to fail under ParallelGC:

----------System.err:(17/1114)----------
java.lang.OutOfMemoryError: Java heap space
at java.base/java.util.Base64$Decoder.decode(Base64.java:569)
at TestEncodingDecodingLength.main(TestEncodingDecodingLength.java:56)
at java.base/java.lang.invoke.LambdaForm$DMH/0x000001e001002000.invokeStatic(LambdaForm$DMH)
at java.base/java.lang.invoke.LambdaForm$MH/0x000001e001003400.invoke(LambdaForm$MH)
at java.base/java.lang.invoke.Invokers$Holder.invokeExact_MT(Invokers$Holder)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invokeImpl(DirectMethodHandleAccessor.java:154)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
at java.base/java.lang.Thread.runWith(Thread.java:1588)
at java.base/java.lang.Thread.run(Thread.java:1575)

JavaTest Message: Test threw exception: java.lang.OutOfMemoryError: Java heap space
JavaTest Message: shutting down test

The test likely needs adjusting to account for the changes in ParallelGC behaviour, but initially assignng to GC team for investigation in case JDK-8330670 needs reconsideration.