Add support for Encode and Decode of Pin<Box<T>>

[nixpulvis]

Allows for encoding and decoding things like Pin<Box<T>>.

Closes #104

[finnbear]

Thanks, I'm curious, why not do it the simple way?

(#104 (comment))

[nixpulvis]

I tried it, but it failed on conflicted impls. Perhaps you know more about that. I could dig more into it tomorrow perhaps.

[finnbear]

Thanks, idk what happened, but my copy of bitcode seemed to compile with that line. When I tried again, it failed as you saw. Maybe the file didn't save after I edited it the first time.

It seems the issue is Pin<T> does not implement From<T> for any T, just Box<...>: https://doc.rust-lang.org/std/pin/struct.Pin.html#impl-From%3CBox%3CT,+A%3E%3E-for-Pin%3CBox%3CT,+A%3E%3E (and there is a similar restriction for Deref).

In light of that, I agree with your approach.

Please remove the unnecessary Deref bound from Decode and fix the formatting issue that the Build CI is failing on. The MSRV issue isn't your fault.