8001591: NMT: assertion failed: assert(rec->addr() + rec->size() <= cur->base()) failed: Can not overlap in memSnapshot.cpp
Summary: NMT should allow overlapping committed regions as long as they belong to the same reserved region
Reviewed-by: dholmes, coleenp

Summary: Enhanced virtual memory tracking to track committed regions as well as reserved regions, so NMT now can generate virtual memory map.
Reviewed-by: acorn, coleenp

7181995: NMT ON: NMT assertion failure assert(cur_vm->is_uncommit_record() || cur_vm->is_deallocation_record
Summary: Fixed virtual memory records merge and promotion logic, should be based on sequence number vs. base address order
Reviewed-by: coleenp, acorn

7191124: Optimized build is broken due to inconsistent use of DEBUG_ONLY and NOT_PRODUCT macros in NMT
Summary: Updated all related variables and methods to use NOT_PRODUCT macros
Reviewed-by: coleenp, acorn, kvn

7187429: NMT ON: Merge failure should cause NMT to shutdown
Summary: Fixed NMT assertion failures
Reviewed-by: acorn, kvn

Summary: Changed _query_lock to heap object from static object. Also fixed _query_lock and snapshot lock ranks, so they can participate deadlock detection.
Reviewed-by: coleenp, dholmes, kvn

7151532: DCmd for hotspot native memory tracking
Summary: Implementation of native memory tracking phase 1, which tracks VM native memory usage, and related DCmd
Reviewed-by: acorn, coleenp, fparain