Implement NullPrecon operator for CUDA
This MR implement the CUDA version of the NullPrecon operator.
It also disable Wpedantic when using CUDA to avoid style of line directive is a GCC extension warning
Edited by Jacques Xing
This MR implement the CUDA version of the NullPrecon operator.
It also disable Wpedantic when using CUDA to avoid style of line directive is a GCC extension warning