Give up on NonZeroUsize memory layout optimization with unstable features.
Give up on NonZeroUsize memory layout optimization with unstable features.

I’m not confident of the implications regarding variance, dropck, struct
aliasing, etc. when this is extended to generic `*const T` and `*mut T`.

Release builds should use `unstable` to enable other optimizations anyway.

thiagopnts/servo,canaltinova/servo,rnestler/servo,larsbergstrom/servo,splav/servo,cbrewster/servo,dati91/servo,dati91/servo,notriddle/servo,rnestler/servo,thiagopnts/servo,emilio/servo,mattnenterprise/servo,emilio/servo,SimonSapin/servo,peterjoel/servo,szeged/servo,ConnorGBrewster/servo,larsbergstrom/servo,paulrouget/servo,cbrewster/servo,mattnenterprise/servo,CJ8664/servo,ConnorGBrewster/servo,sadmansk/servo,anthgur/servo,cbrewster/servo,szeged/servo,saneyuki/servo,szeged/servo,SimonSapin/servo,saneyuki/servo,avadacatavra/servo,eddyb/servo,mattnenterprise/servo,dsandeephegde/servo,ConnorGBrewster/servo,jimberlage/servo,thiagopnts/servo,pyfisch/servo,fiji-flo/servo,CJ8664/servo,canaltinova/servo,nnethercote/servo,KiChjang/servo,mbrubeck/servo,paulrouget/servo,paulrouget/servo,saneyuki/servo,cbrewster/servo,notriddle/servo,jimberlage/servo,nnethercote/servo,splav/servo,emilio/servo,splav/servo,dsandeephegde/servo,canaltinova/servo,pyfisch/servo,DominoTree/servo,notriddle/servo,rnestler/servo,saneyuki/servo,KiChjang/servo,canaltinova/servo,nnethercote/servo,ConnorGBrewster/servo,paulrouget/servo,sadmansk/servo,KiChjang/servo,avadacatavra/servo,dsandeephegde/servo,DominoTree/servo,upsuper/servo,fiji-flo/servo,pyfisch/servo,cbrewster/servo,KiChjang/servo,ConnorGBrewster/servo,SimonSapin/servo,KiChjang/servo,thiagopnts/servo,dati91/servo,canaltinova/servo,thiagopnts/servo,anthgur/servo,emilio/servo,KiChjang/servo,paulrouget/servo,eddyb/servo,DominoTree/servo,dsandeephegde/servo,notriddle/servo,pyfisch/servo,pyfisch/servo,eddyb/servo,sadmansk/servo,SimonSapin/servo,thiagopnts/servo,peterjoel/servo,fiji-flo/servo,sadmansk/servo,szeged/servo,fiji-flo/servo,avadacatavra/servo,fiji-flo/servo,DominoTree/servo,saneyuki/servo,nnethercote/servo,paulrouget/servo,CJ8664/servo,saneyuki/servo,notriddle/servo,mbrubeck/servo,canaltinova/servo,avadacatavra/servo,dati91/servo,larsbergstrom/servo,rnestler/servo,eddyb/servo,emilio/servo,anthgur/servo,notriddle/servo,SimonSapin/servo,larsbergstrom/servo,splav/servo,rnestler/servo,nnethercote/servo,avadacatavra/servo,eddyb/servo,notriddle/servo,canaltinova/servo,nnethercote/servo,paulrouget/servo,dsandeephegde/servo,paulrouget/servo,mbrubeck/servo,mbrubeck/servo,pyfisch/servo,pyfisch/servo,upsuper/servo,anthgur/servo,upsuper/servo,KiChjang/servo,larsbergstrom/servo,upsuper/servo,avadacatavra/servo,SimonSapin/servo,dati91/servo,peterjoel/servo,splav/servo,peterjoel/servo,emilio/servo,avadacatavra/servo,emilio/servo,fiji-flo/servo,anthgur/servo,SimonSapin/servo,mattnenterprise/servo,nnethercote/servo,dsandeephegde/servo,sadmansk/servo,szeged/servo,peterjoel/servo,saneyuki/servo,DominoTree/servo,DominoTree/servo,DominoTree/servo,jimberlage/servo,CJ8664/servo,notriddle/servo,jimberlage/servo,CJ8664/servo,jimberlage/servo,dati91/servo,szeged/servo,nnethercote/servo,anthgur/servo,dati91/servo,nnethercote/servo,peterjoel/servo,larsbergstrom/servo,splav/servo,cbrewster/servo,DominoTree/servo,emilio/servo,upsuper/servo,jimberlage/servo,jimberlage/servo,SimonSapin/servo,eddyb/servo,eddyb/servo,larsbergstrom/servo,jimberlage/servo,CJ8664/servo,canaltinova/servo,nnethercote/servo,CJ8664/servo,mbrubeck/servo,notriddle/servo,splav/servo,mbrubeck/servo,sadmansk/servo,mattnenterprise/servo,splav/servo,KiChjang/servo,pyfisch/servo,DominoTree/servo,peterjoel/servo,rnestler/servo,rnestler/servo,anthgur/servo,thiagopnts/servo,mbrubeck/servo,szeged/servo,notriddle/servo,mattnenterprise/servo,upsuper/servo,fiji-flo/servo,dsandeephegde/servo,splav/servo,peterjoel/servo,upsuper/servo,ConnorGBrewster/servo,DominoTree/servo,pyfisch/servo,dati91/servo,mattnenterprise/servo,upsuper/servo,larsbergstrom/servo,jimberlage/servo,thiagopnts/servo,saneyuki/servo,emilio/servo,CJ8664/servo,szeged/servo,paulrouget/servo,mbrubeck/servo,anthgur/servo,rnestler/servo,larsbergstrom/servo,larsbergstrom/servo,paulrouget/servo,fiji-flo/servo,peterjoel/servo,saneyuki/servo,pyfisch/servo,KiChjang/servo,avadacatavra/servo,eddyb/servo,saneyuki/servo,szeged/servo,ConnorGBrewster/servo,cbrewster/servo,sadmansk/servo,ConnorGBrewster/servo,emilio/servo,KiChjang/servo,cbrewster/servo,peterjoel/servo,splav/servo,dsandeephegde/servo,sadmansk/servo,szeged/servo,mattnenterprise/servo