The VMOp type `JvmtiPostObjectFree` was introduced with JDK-8212879 but was never used for any `VM_Operation`. The `VM_Operation` introduced in that patch `VM_JvmtiPostObjectFree` used the `Cleanup` VMOp type instead.

`VM_JvmtiPostObjectFree` was later removed completely with JDK-8256811. So there is no need for this VMOp type.

I suggest a trivial removal of this unused symbol.