- Implemented some syscall for MacOSX
- tested on : El Capitan 10.11 x86_64
- make self hosted test run on macosx
- modified run_test so it does not fail when parseh throws
  warnings (most of them are related to buildin types from
  gcc that arent defined in header files and unions)
- making -mmacosx-version-min and -mios-version-min works like
  gcc (command line paramers have precedence over enviroment variables)