added implementation of barrier code for MSVC
added implementation of barrier code for MSVC

nikhilsinghmus/csound,nikhilsinghmus/csound,nikhilsinghmus/csound,nikhilsinghmus/csound,nikhilsinghmus/csound,nikhilsinghmus/csound,nikhilsinghmus/csound,nikhilsinghmus/csound,nikhilsinghmus/csound,nikhilsinghmus/csound