Add Boot_Time.getMonotonicTime for benchmarking purpose
Add Boot_Time.getMonotonicTime for benchmarking purpose

* The unit is the nanosecond and it uses a monotonic clock,
  C++'s steady_clock.
* It is slightly expensive on 32-bit as it will return a BigInt.

eregon/mozart2,Angeldude/mozart2,Angeldude/mozart2,yjaradin/mozart2,mozart/mozart2,layus/mozart2,eregon/mozart2,yjaradin/mozart2,dianacgr/mozart2,layus/mozart2,Angeldude/mozart2,dianacgr/mozart2,eregon/mozart2,layus/mozart2,dianacgr/mozart2,mozart/mozart2,yjaradin/mozart2,mozart/mozart2