8148244: Finalize and integrate GTest implementation
Reviewed-by: jwilhelm, erikj
Contributed-by: stefan.karlsson@oracle.com, stefan.sarne@oracle.com, jesper.wilhelmsson@oracle.com, erik.helin@oracle.com, alexandre.iline@oracle.com, igor.ignatyev@oracle.com, erik.joelsson@oracle.com

8150601: Remove the old Hotspot build system
Reviewed-by: ihse