Exclude 2 more tests using G1 on jdk8 arm

Author: zzambers

openjdk/excludes/ProblemList_openjdk8.txt

@@ -46,6 +46,8 @@ compiler/8209951/TestCipherBlockChainingEncrypt.java https://github.com/adoptium
 gc/g1/TestHumongousCodeCacheRoots.java https://github.com/adoptium/aqa-tests/issues/2818 aix-all,linux-arm
 gc/whitebox/TestConcMarkCycleWB.java https://bugs.openjdk.java.net/browse/JDK-8067368 linux-arm
 gc/metaspace/TestMetaspaceMemoryPool.java https://github.com/adoptium/aqa-tests/issues/2708 generic-all
+gc/ergonomics/TestDynamicNumberOfGCThreads.java https://github.com/adoptium/aqa-tests/issues/5019 linux-arm
+gc/class_unloading/TestG1ClassUnloadingHWM.java https://github.com/adoptium/aqa-tests/issues/5019 linux-arm
 gc/TestMemoryMXBeansAndPoolsPresence.java https://github.com/adoptium/aqa-tests/issues/3297 linux-arm
 gc/g1/mixedgc/TestOldGenCollectionUsage.java https://github.com/adoptium/aqa-tests/issues/3297 linux-arm
 gc/g1/Test2GbHeap.java https://github.com/adoptium/aqa-tests/issues/3297 linux-arm