Integer overflow in `hyper`'s parsing of the `Transfer-Encoding` header leads to data loss

When decoding chunk sizes that are too large, hyper’s code would encounter an integer overflow. Depending on the situation,
this could lead to data loss from an incorrect total size, or in rarer cases, a request smuggling attack.

To be vulnerable, you must be using hyper for any HTTP/1 purpose, including as a client or server, and consumers must send
requests or responses that specify a chunk size greater than 18 exabytes. For a possible request smuggling attack to be possible,
any upstream proxies must accept a chunk size greater than 64 bits.