If we bump the JDK version to 10 we trigger the warnings related to flags that should be removed in 10:

Java HotSpot(TM) 64-Bit Server VM warning: Global variable for expired flag entry "AutoGCSelectPauseMillis" should be removed
Java HotSpot(TM) 64-Bit Server VM warning: Global variable for expired flag entry "UseAutoGCSelectPolicy" should be removed
Java HotSpot(TM) 64-Bit Server VM warning: Global variable for expired flag entry "UseParNewGC" should be removed
Java HotSpot(TM) 64-Bit Server VM warning: Global variable for expired flag entry "ExplicitGCInvokesConcurrentAndUnloadsClasses" should be removed
Java HotSpot(TM) 64-Bit Server VM warning: Global variable for obsolete special flag entry "ConvertSleepToYield" should be removed
Java HotSpot(TM) 64-Bit Server VM warning: Global variable for obsolete special flag entry "ConvertYieldToSleep" should be removed

We then trip an assert that makes it impossible to build JDK 10 without first fixing this issue (though the assert should be removed as a seperate issue).

We need to delete the table entries, delete the global variables and delete all code that uses the non-default value of the global variable being deleted (if not already ignored).