Reflective access of java.nio.DirectByteBuffer.cleaner() not allowed from JDK-16.

NetBeans seems to be hacking into a few JDK internals and this will be disallowed by default from Java 16 onwards. Needs to replace it from  Unsafe.invokeCleaner 

WARNING: Illegal reflective access by
org.netbeans.core.output2.FileMapStorage
(jar:file:/Users/albatem/netbeans-12.3/platform/modules/org-netbeans-core-output2.jar!/)
to method java.nio.DirectByteBuffer.cleaner()
     at
org.netbeans.core.output2.FileMapStorage.unmap(FileMapStorage.java:311)
     at
org.netbeans.core.output2.FileMapStorage.access$400(FileMapStorage.java:38)
     at
org.netbeans.core.output2.FileMapStorage$MappedBufferResource.decRefs(FileMapStorage.java:479)
     at
org.netbeans.core.output2.FileMapStorage.updateContents(FileMapStorage.java:377)
     at
org.netbeans.core.output2.FileMapStorage.getReadBuffer(FileMapStorage.java:341)
     at
org.netbeans.core.output2.AbstractLines.getText(AbstractLines.java:125)
     at
org.netbeans.core.output2.OutputDocument.getText(OutputDocument.java:195)