Implement Eq for Cell and RefCell.
Implement Eq for Cell and RefCell.

`core::cell::Cell<T>` and `core::cell::RefCell<T>` currently implement
`PartialEq` when `T` does, and just defer to comparing `T` values.
There is no reason the same shouldn’t apply to `Eq`.

This enables `#[derive(Eq, PartialEq)]` on e.g.
structs that have a `RefCell` field.

mihneadb/rust,pelmers/rust,vhbit/rust,l0kod/rust,TheNeikos/rust,nwin/rust,andars/rust,jashank/rust,krzysz00/rust,mihneadb/rust,zachwick/rust,jashank/rust,l0kod/rust,aidancully/rust,sae-bom/rust,zubron/rust,aneeshusa/rust,pshc/rust,zachwick/rust,ejjeong/rust,pshc/rust,graydon/rust,pshc/rust,zubron/rust,zachwick/rust,l0kod/rust,aidancully/rust,vhbit/rust,sae-bom/rust,TheNeikos/rust,mvdnes/rust,jroesch/rust,aidancully/rust,robertg/rust,reem/rust,dwillmer/rust,aidancully/rust,seanrivera/rust,KokaKiwi/rust,zubron/rust,jroesch/rust,zubron/rust,jroesch/rust,TheNeikos/rust,mihneadb/rust,aneeshusa/rust,krzysz00/rust,kwantam/rust,omasanori/rust,TheNeikos/rust,reem/rust,zubron/rust,pelmers/rust,graydon/rust,nwin/rust,GBGamer/rust,KokaKiwi/rust,KokaKiwi/rust,KokaKiwi/rust,robertg/rust,aidancully/rust,aepsil0n/rust,jroesch/rust,l0kod/rust,andars/rust,reem/rust,aepsil0n/rust,jroesch/rust,aneeshusa/rust,reem/rust,mvdnes/rust,zachwick/rust,l0kod/rust,andars/rust,graydon/rust,dwillmer/rust,jashank/rust,zubron/rust,GBGamer/rust,aidancully/rust,reem/rust,seanrivera/rust,KokaKiwi/rust,reem/rust,seanrivera/rust,pshc/rust,nwin/rust,krzysz00/rust,TheNeikos/rust,jashank/rust,omasanori/rust,mvdnes/rust,l0kod/rust,graydon/rust,GBGamer/rust,mihneadb/rust,ejjeong/rust,pelmers/rust,mvdnes/rust,pshc/rust,vhbit/rust,pshc/rust,mihneadb/rust,aepsil0n/rust,GBGamer/rust,GBGamer/rust,nwin/rust,vhbit/rust,ejjeong/rust,kwantam/rust,robertg/rust,GBGamer/rust,pelmers/rust,dwillmer/rust,kwantam/rust,sae-bom/rust,nwin/rust,nwin/rust,graydon/rust,TheNeikos/rust,seanrivera/rust,seanrivera/rust,nwin/rust,omasanori/rust,jroesch/rust,mvdnes/rust,vhbit/rust,andars/rust,dwillmer/rust,dwillmer/rust,zachwick/rust,jashank/rust,dwillmer/rust,krzysz00/rust,mihneadb/rust,vhbit/rust,kwantam/rust,zubron/rust,KokaKiwi/rust,seanrivera/rust,aneeshusa/rust,graydon/rust,GBGamer/rust,nwin/rust,jroesch/rust,l0kod/rust,pelmers/rust,krzysz00/rust,aepsil0n/rust,robertg/rust,aneeshusa/rust,krzysz00/rust,jroesch/rust,dwillmer/rust,aepsil0n/rust,jashank/rust,sae-bom/rust,vhbit/rust,andars/rust,jashank/rust,zubron/rust,robertg/rust,zachwick/rust,sae-bom/rust,kwantam/rust,pshc/rust,aneeshusa/rust,ejjeong/rust,l0kod/rust,ejjeong/rust,omasanori/rust,dwillmer/rust,omasanori/rust,aepsil0n/rust,vhbit/rust,pshc/rust,GBGamer/rust,andars/rust,pelmers/rust,kwantam/rust,mvdnes/rust,sae-bom/rust,jashank/rust,robertg/rust,ejjeong/rust,omasanori/rust