Auto merge of #10870 - axitkhurana:do-parse-integer-return-value, r=KiChjang
Auto merge of #10870 - axitkhurana:do-parse-integer-return-value, r=KiChjang

Return a Result<i64, ()> from do_parse_integer

Fixes #10860

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