Auto merge of #6360 - fbau123:6315-tests-default-cpu-mode, r=Ms2ger
Auto merge of #6360 - fbau123:6315-tests-default-cpu-mode, r=Ms2ger

#6315
 
Set 'mach test-ref' default render mode to cpu and added a cli argument to 'mach test' to be able to select the render-mode, also renamed the 'kind' argument from 'test-ref' to '--render-mode' for coherence with reftest.rs

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zentner-kyle/servo,dhananjay92/servo,sadmansk/servo,mbrubeck/servo,g-k/servo,dvberkel/servo,upsuper/servo,nnethercote/servo,s142857/servo,runarberg/servo,cbrewster/servo,tschneidereit/servo,emilio/servo,codemac/servo,nerith/servo,zentner-kyle/servo,larsbergstrom/servo,tempbottle/servo,rentongzhang/servo,ryancanhelpyou/servo,GyrosOfWar/servo,brendandahl/servo,DominoTree/servo,DominoTree/servo,notriddle/servo,s142857/servo,KiChjang/servo,vks/servo,rnestler/servo,SimonSapin/servo,jimberlage/servo,szeged/servo,karlito40/servo,avadacatavra/servo,karlito40/servo,canaltinova/servo,WriterOfAlicrow/servo,huonw/servo,aidanhs/servo,dvberkel/servo,akosel/servo,saneyuki/servo,tschneidereit/servo,upsuper/servo,walac/servo,karlito40/servo,mattnenterprise/servo,rentongzhang/servo,dhananjay92/servo,brendandahl/servo,pyfisch/servo,meh/servo,dvberkel/servo,saratang/servo,wartman4404/servo,dhananjay92/servo,emilio/servo,SimonSapin/servo,jlegendary/servo,boghison/servo,CJ8664/servo,szeged/servo,pyecs/servo,samfoo/servo,pyecs/servo,tafia/servo,youprofit/servo,fiji-flo/servo,walac/servo,kindersung/servo,jgraham/servo,peterjoel/servo,notriddle/servo,paulrouget/servo,anthgur/servo,codemac/servo,anthgur/servo,szeged/servo,mbrubeck/servo,dagnir/servo,CJ8664/servo,ConnorGBrewster/servo,thiagopnts/servo,pyfisch/servo,youprofit/servo,walac/servo,dati91/servo,tschneidereit/servo,thiagopnts/servo,eddyb/servo,ryancanhelpyou/servo,rnestler/servo,meh/servo,brendandahl/servo,caldwell/servo,nnethercote/servo,aweinstock314/servo,DominoTree/servo,A-deLuna/servo,rentongzhang/servo,CJ8664/servo,vks/servo,aidanhs/servo,dati91/servo,ConnorGBrewster/servo,splav/servo,fiji-flo/servo,hyowon/servo,nnethercote/servo,mt2d2/servo,samfoo/servo,pgonda/servo,zentner-kyle/servo,dvberkel/servo,upsuper/servo,bjwbell/servo,meh/servo,samfoo/servo,pgonda/servo,AnthonyBroadCrawford/servo,RenaudParis/servo,dhananjay92/servo,dagnir/servo,hyowon/servo,saneyuki/servo,runarberg/servo,tempbottle/servo,vks/servo,runarberg/servo,canaltinova/servo,notriddle/servo,aweinstock314/servo,bjwbell/servo,dagnir/servo,mbrubeck/servo,avadacatavra/servo,aidanhs/servo,szeged/servo,jimberlage/servo,nnethercote/servo,zentner-kyle/servo,mdibaiee/servo,notriddle/servo,aidanhs/servo,aweinstock314/servo,peterjoel/servo,dsandeephegde/servo,nrc/servo,kindersung/servo,akosel/servo,AnthonyBroadCrawford/servo,rnestler/servo,s142857/servo,walac/servo,aidanhs/servo,jlegendary/servo,larsbergstrom/servo,notriddle/servo,vks/servo,peterjoel/servo,saratang/servo,pyfisch/servo,codemac/servo,g-k/servo,cbrewster/servo,deokjinkim/servo,saneyuki/servo,avadacatavra/servo,nrc/servo,rentongzhang/servo,fiji-flo/servo,saratang/servo,mt2d2/servo,sadmansk/servo,dhananjay92/servo,meh/servo,j3parker/servo,cbrewster/servo,AnthonyBroadCrawford/servo,dvberkel/servo,cbrewster/servo,peterjoel/servo,runarberg/servo,RenaudParis/servo,tempbottle/servo,WriterOfAlicrow/servo,avadacatavra/servo,hyowon/servo,dagnir/servo,eddyb/servo,notriddle/servo,boghison/servo,s142857/servo,huonw/servo,s142857/servo,brendandahl/servo,meh/servo,codemac/servo,bjwbell/servo,kindersung/servo,kindersung/servo,RenaudParis/servo,mdibaiee/servo,runarberg/servo,runarberg/servo,sadmansk/servo,caldwell/servo,larsbergstrom/servo,jdramani/servo,zentner-kyle/servo,szeged/servo,s142857/servo,ConnorGBrewster/servo,g-k/servo,akosel/servo,tschneidereit/servo,wartman4404/servo,nick-thompson/servo,notriddle/servo,canaltinova/servo,splav/servo,deokjinkim/servo,KiChjang/servo,jimberlage/servo,caldwell/servo,deokjinkim/servo,mbrubeck/servo,g-k/servo,tempbottle/servo,bjwbell/servo,boghison/servo,KiChjang/servo,samfoo/servo,canaltinova/servo,saneyuki/servo,upsuper/servo,nerith/servo,A-deLuna/servo,mt2d2/servo,szeged/servo,dati91/servo,dsandeephegde/servo,nick-thompson/servo,eddyb/servo,peterjoel/servo,KiChjang/servo,DominoTree/servo,akosel/servo,DominoTree/servo,brendandahl/servo,aidanhs/servo,splav/servo,deokjinkim/servo,anthgur/servo,caldwell/servo,hyowon/servo,aweinstock314/servo,A-deLuna/servo,KiChjang/servo,RenaudParis/servo,karlito40/servo,jdramani/servo,boghison/servo,mdibaiee/servo,avadacatavra/servo,deokjinkim/servo,hyowon/servo,steveklabnik/servo,anthgur/servo,mattnenterprise/servo,rnestler/servo,jdramani/servo,cbrewster/servo,rnestler/servo,splav/servo,rentongzhang/servo,fiji-flo/servo,jimberlage/servo,bjwbell/servo,GyrosOfWar/servo,KiChjang/servo,tafia/servo,sadmansk/servo,saneyuki/servo,larsbergstrom/servo,paulrouget/servo,cbrewster/servo,rnestler/servo,nrc/servo,AnthonyBroadCrawford/servo,dati91/servo,anthgur/servo,akosel/servo,upsuper/servo,fiji-flo/servo,upsuper/servo,szeged/servo,mattnenterprise/servo,mdibaiee/servo,szeged/servo,g-k/servo,peterjoel/servo,tempbottle/servo,DominoTree/servo,youprofit/servo,jdramani/servo,caldwell/servo,anthgur/servo,DominoTree/servo,meh/servo,WriterOfAlicrow/servo,nerith/servo,notriddle/servo,codemac/servo,pyfisch/servo,A-deLuna/servo,tempbottle/servo,paulrouget/servo,cbrewster/servo,jlegendary/servo,tafia/servo,pyfisch/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