Rollup merge of #33420 - durka:patch-20, r=alexcrichton
Rollup merge of #33420 - durka:patch-20, r=alexcrichton

implement RFC 1521

Adds documentation to Clone, specifying that Copy types should have a trivial Clone impl.

Fixes #33416.

I tried to use "should" and "must" as defined [here](https://tools.ietf.org/html/rfc2119).

cc @ubsan

GBGamer/rust,GBGamer/rust,aidancully/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,aidancully/rust,GBGamer/rust,graydon/rust,graydon/rust,GBGamer/rust,GBGamer/rust,graydon/rust,graydon/rust,graydon/rust,graydon/rust,GBGamer/rust,aidancully/rust,aidancully/rust