7151532: DCmd for hotspot native memory tracking
Implementation of native memory tracking phase 1, which tracks VM native memory usage, and related DCmd
Reviewed-by: acorn, coleenp, fparain
Get java.io.tmpdir property in os::get_temp_directory() and call this instead of harcoding "/tmp". Don't assume trailing file_separator either.
Reviewed-by: dholmes, kamg