Please consider adding Reset to crypto/cipher/ctr

[Juliusz Chroboczek]

Hi,

Now that the tree is open again, could somebody please consider the
issue described at

https://github.com/golang/go/issues/39365

In short, we're looking for a way to reuse previously allocated
crypto/cipher/ctr structures, rather than having to allocate a new one
every time we need a new CTR. It seems like a fairly minor library
addition, and it would fix one of the two main sources of allocation in
the Pion WebRTC library.

Thanks,

-- Juliusz Chroboczek