Is it possible to propose changes to the Cuda/C++ language, and if so, how?

I am currently thinking about the behaviour of __host__ __device__ specifiers, and trying to solve problems when a __host__ __device__ function calls a __host__ or __device__ function. Which usually results in a compiler warning or error.
Since this happens a lot in generic code (which I write), I have lots of these warnings.

Furthermore, I thought about solutions which would solve this problem quite elegant, but would require a language change. Thus my question: Is there some way to make proposals for language changes, like it is in C++?

you can file a bug. In addition to bugs, that mechanism can be used to request enhancements of nearly any time to CUDA or CUDA documentation.