Backport broken scatter/gather Signatures

[Axel Huebl]

Ubuntu 18.04 LTS ships CUDA 9.1.85 which is broken with provided GCC compilers in a slightly complex way.

By default, the g++ compiler version is 7.4.0, which is not supported by CUDA/NVCC 9.1.85.
Next, CUDA/NVCC 9.1.85 should have provided support for g++ 6. But the release overlooked an incompatibility with std::tuple which renders this compiler combination not useful either:
  https://gist.github.com/ax3l/9489132

Consequently, users that want to use mature C++11/14 features can still switch to install a g++-5 package on Ubuntu 18.04 but this compiler has another set of bugs in signatures of gather/scatter intrinsics which were fixed in later GCC releases. This fix was unfortunately not backported to GCC 5.5 .
  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=76731

In order to make NVCC+GCC work together on Ubuntu 18.04, I would recommend to backport the small patches of three intrinsic files with broken signatures to the g++-5 (specifically the libgcc-5-dev) packages:
  https://stackoverflow.com/a/50815334/2719194

Thanks a lot for considering,
Axel