sleef: Sleef functions can't be inlined

In PyTorch, we’d like to use Sleef’s vectorized implementation of elementary functions as building blocks. For example, we’d like to implement a vectorized sigmoid() function using exp. However, calling into Sleef’s exp() is expensive because it incurs the cost of a non-inlineable function call.

It would be great if Sleef provided the instruction-set specific vectorized functions in a header file, or some other way that can be inlined by the compiler.