Auto merge of #11160 - bholley:zero_gecko_struct, r=mbrubeck
Auto merge of #11160 - bholley:zero_gecko_struct, r=mbrubeck

Only use zeroed memory for gecko style structs, not the wrapper servo struct.

So that we don't clobber the drop flags.

This is a regression from #11121.

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