Duplicate values in enum MemoryType (Native Memory Tracking)

There are two enum entries with the same value in enum MemoryType in allocation.hpp.

mtTracing and mtDontTrack are both defined as 0x0F00. This probably makes memory allocated by JFR invisible/untrackable.

enum MemoryType {
...
  mtClassShared = 0x0D00, // class data sharing
  mtTest = 0x0E00, // Test type for verifying NMT
  mtTracing = 0x0F00, // memory used for Tracing
  mt_number_of_types = 0x000F, // number of memory types (mtDontTrack
                                 // is not included as validate type)
  mtDontTrack = 0x0F00, // memory we do not or cannot track
  mt_masks = 0x7F00,
...
}