* Reimplement the check_nan_inf function as check_numerics kernel.

* Remove the cpu implemention to phi.

* Add ifdef for the including of omp.h.

* Move the use of FLAGS_check_nan_inf_level out of header file.

* Implement a common PrintAndThrowError function.

* Fix the error using of __NVCC__, which should be instead with __CUDA_ARCH__.

* Add dependency of phi.

* Polish codes and unittest.