This commit updates the cpp_synchronization to run on the "POSIX
architecture" boards such as `native_posix`, since the POSIX arch now
properly supports the main() defined in a C++ source file.
Signed-off-by: Stephanos Ioannidis <stephanos.ioannidis@nordicsemi.no>
XCC (based on GCC 4.2) doesn't support C++11, and can't build those
tests. So exclude them from twister.
Signed-off-by: Ederson de Souza <ederson.desouza@intel.com>