CUDA __popc and __popcll parameter have wrong signedness

[DDoSolitary]

According to CUDA doc, __popc and __popcll accept unsigned arguments

 __device__ ​ int __popc ( unsigned int  x );
 __device__ ​ int __popcll ( unsigned long long int x );

but Clang's version is signed

llvm-project/clang/lib/Headers/__clang_cuda_device_functions.h

Lines 505 to 506 in 6098d7d

	__DEVICE__ int __popc(int __a) { return __nv_popc(__a); }
	__DEVICE__ int __popcll(long long __a) { return __nv_popcll(__a); }

While this is mostly harmless, it causes a lot of "narrowing conversion from unsigned to signed is implementation defined" warnings when I was trying to check existing CUDA code with clang-tidy.

[Artem-B]

Should be fixed by 2a702ec