Summary: Disallow increasing native memory tracking level
Reviewed-by: hseigel, ctornqvi, gtriantafill

8058818: Allocation of more then 1G of memory using Unsafe.allocateMemory is still causing a fatal error on 32bit platforms
Summary: The assert was firing for NMT_Off and minimal too even though the size isn't used.
Reviewed-by: gtriantafill, dholmes

Summary: Enhance scalability of native memory tracking
Reviewed-by: coleenp, ctornqvi, gtriantafill