stylo: Do not skip parent display-based style fixups for NAC that is not a NAC root
stylo: Do not skip parent display-based style fixups for NAC that is not a NAC root

Stylo is currently skipping parent display-based style fixups for all NAC,
whereas we probably only want to do this for NAC roots.

In this patch, we ensure that we skip it for NAC roots, and pseudo-elements,
but not other NAC.

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