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

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