System.ObjectModel: Add System.Threading to packages.config for tests
System.ObjectModel: Add System.Threading to packages.config for tests

Needed for the Mono mcs compiler, see #774.

khdang/corefx,ericstj/corefx,shrutigarg/corefx,richlander/corefx,thiagodin/corefx,vijaykota/corefx,jmhardison/corefx,Yanjing123/corefx,pallavit/corefx,CherryCxldn/corefx,alphonsekurian/corefx,gregg-miskelly/corefx,billwert/corefx,krytarowski/corefx,rahku/corefx,jhendrixMSFT/corefx,andyhebear/corefx,Frank125/corefx,benjamin-bader/corefx,zhenlan/corefx,krytarowski/corefx,shiftkey-tester/corefx,jlin177/corefx,cartermp/corefx,xuweixuwei/corefx,wtgodbe/corefx,ericstj/corefx,stone-li/corefx,axelheer/corefx,vidhya-bv/corefx-sorting,twsouthwick/corefx,viniciustaveira/corefx,dotnet-bot/corefx,tstringer/corefx,iamjasonp/corefx,marksmeltzer/corefx,axelheer/corefx,oceanho/corefx,stone-li/corefx,vrassouli/corefx,tijoytom/corefx,claudelee/corefx,CloudLens/corefx,dotnet-bot/corefx,krk/corefx,nbarbettini/corefx,DnlHarvey/corefx,ericstj/corefx,YoupHulsebos/corefx,vrassouli/corefx,josguil/corefx,jlin177/corefx,iamjasonp/corefx,ViktorHofer/corefx,fgreinacher/corefx,bitcrazed/corefx,rjxby/corefx,kkurni/corefx,mazong1123/corefx,JosephTremoulet/corefx,PatrickMcDonald/corefx,fernando-rodriguez/corefx,stormleoxia/corefx,mokchhya/corefx,ellismg/corefx,krytarowski/corefx,gkhanna79/corefx,jhendrixMSFT/corefx,erpframework/corefx,ravimeda/corefx,stone-li/corefx,bpschoch/corefx,zhangwenquan/corefx,marksmeltzer/corefx,PatrickMcDonald/corefx,chenkennt/corefx,KrisLee/corefx,dtrebbien/corefx,manu-silicon/corefx,mokchhya/corefx,marksmeltzer/corefx,janhenke/corefx,gregg-miskelly/corefx,vs-team/corefx,uhaciogullari/corefx,Ermiar/corefx,JosephTremoulet/corefx,iamjasonp/corefx,dkorolev/corefx,Chrisboh/corefx,jeremymeng/corefx,manu-silicon/corefx,SGuyGe/corefx,misterzik/corefx,krytarowski/corefx,alexperovich/corefx,mazong1123/corefx,vijaykota/corefx,twsouthwick/corefx,CherryCxldn/corefx,ravimeda/corefx,stephenmichaelf/corefx,krk/corefx,Chrisboh/corefx,n1ghtmare/corefx,zhangwenquan/corefx,s0ne0me/corefx,gkhanna79/corefx,dhoehna/corefx,690486439/corefx,YoupHulsebos/corefx,dotnet-bot/corefx,gabrielPeart/corefx,Ermiar/corefx,shiftkey-tester/corefx,anjumrizwi/corefx,bpschoch/corefx,richlander/corefx,DnlHarvey/corefx,twsouthwick/corefx,alexandrnikitin/corefx,jcme/corefx,manu-silicon/corefx,PatrickMcDonald/corefx,kkurni/corefx,the-dwyer/corefx,Winsto/corefx,alphonsekurian/corefx,zmaruo/corefx,shana/corefx,weltkante/corefx,axelheer/corefx,s0ne0me/corefx,kkurni/corefx,jlin177/corefx,rjxby/corefx,stephenmichaelf/corefx,axelheer/corefx,zhenlan/corefx,YoupHulsebos/corefx,Jiayili1/corefx,Petermarcu/corefx,ellismg/corefx,viniciustaveira/corefx,zhenlan/corefx,rjxby/corefx,pallavit/corefx,nbarbettini/corefx,elijah6/corefx,larsbj1988/corefx,anjumrizwi/corefx,spoiledsport/corefx,mmitche/corefx,scott156/corefx,lggomez/corefx,erpframework/corefx,huanjie/corefx,adamralph/corefx,claudelee/corefx,shahid-pk/corefx,Chrisboh/corefx,wtgodbe/corefx,fgreinacher/corefx,yizhang82/corefx,josguil/corefx,oceanho/corefx,benjamin-bader/corefx,fgreinacher/corefx,viniciustaveira/corefx,twsouthwick/corefx,chenxizhang/corefx,jlin177/corefx,benjamin-bader/corefx,Petermarcu/corefx,twsouthwick/corefx,lydonchandra/corefx,shmao/corefx,zmaruo/corefx,brett25/corefx,adamralph/corefx,mmitche/corefx,shana/corefx,popolan1986/corefx,rubo/corefx,stone-li/corefx,JosephTremoulet/corefx,jcme/corefx,gkhanna79/corefx,ravimeda/corefx,jmhardison/corefx,dsplaisted/corefx,tijoytom/corefx,bitcrazed/corefx,cartermp/corefx,shahid-pk/corefx,kyulee1/corefx,Alcaro/corefx,rjxby/corefx,ptoonen/corefx,kyulee1/corefx,jmhardison/corefx,ellismg/corefx,nelsonsar/corefx,alexandrnikitin/corefx,stone-li/corefx,Alcaro/corefx,shimingsg/corefx,SGuyGe/corefx,marksmeltzer/corefx,mmitche/corefx,MaggieTsang/corefx,mellinoe/corefx,CherryCxldn/corefx,oceanho/corefx,mazong1123/corefx,shrutigarg/corefx,ViktorHofer/corefx,seanshpark/corefx,popolan1986/corefx,rahku/corefx,shiftkey-tester/corefx,Winsto/corefx,chaitrakeshav/corefx,matthubin/corefx,tstringer/corefx,destinyclown/corefx,690486439/corefx,rajansingh10/corefx,KrisLee/corefx,s0ne0me/corefx,tijoytom/corefx,seanshpark/corefx,shimingsg/corefx,cydhaselton/corefx,akivafr123/corefx,parjong/corefx,rjxby/corefx,tijoytom/corefx,cnbin/corefx,spoiledsport/corefx,brett25/corefx,nbarbettini/corefx,tijoytom/corefx,MaggieTsang/corefx,JosephTremoulet/corefx,jlin177/corefx,ViktorHofer/corefx,benpye/corefx,Jiayili1/corefx,PatrickMcDonald/corefx,comdiv/corefx,manu-silicon/corefx,nelsonsar/corefx,marksmeltzer/corefx,tstringer/corefx,krytarowski/corefx,DnlHarvey/corefx,ericstj/corefx,lydonchandra/corefx,ptoonen/corefx,pallavit/corefx,dhoehna/corefx,mafiya69/corefx,alexandrnikitin/corefx,nelsonsar/corefx,cartermp/corefx,jlin177/corefx,xuweixuwei/corefx,yizhang82/corefx,JosephTremoulet/corefx,shimingsg/corefx,zhenlan/corefx,dotnet-bot/corefx,alphonsekurian/corefx,vs-team/corefx,mazong1123/corefx,Jiayili1/corefx,lggomez/corefx,comdiv/corefx,zhenlan/corefx,elijah6/corefx,dhoehna/corefx,andyhebear/corefx,iamjasonp/corefx,scott156/corefx,kkurni/corefx,mazong1123/corefx,Priya91/corefx-1,vidhya-bv/corefx-sorting,dhoehna/corefx,gregg-miskelly/corefx,EverlessDrop41/corefx,chenkennt/corefx,thiagodin/corefx,ptoonen/corefx,jeremymeng/corefx,cydhaselton/corefx,bpschoch/corefx,rubo/corefx,billwert/corefx,jeremymeng/corefx,popolan1986/corefx,ellismg/corefx,khdang/corefx,alexperovich/corefx,shahid-pk/corefx,nchikanov/corefx,viniciustaveira/corefx,jcme/corefx,DnlHarvey/corefx,jhendrixMSFT/corefx,mellinoe/corefx,SGuyGe/corefx,yizhang82/corefx,Chrisboh/corefx,stone-li/corefx,comdiv/corefx,SGuyGe/corefx,khdang/corefx,khdang/corefx,SGuyGe/corefx,parjong/corefx,jhendrixMSFT/corefx,nchikanov/corefx,iamjasonp/corefx,arronei/corefx,nbarbettini/corefx,janhenke/corefx,tstringer/corefx,benjamin-bader/corefx,dhoehna/corefx,ravimeda/corefx,erpframework/corefx,dsplaisted/corefx,gkhanna79/corefx,vs-team/corefx,richlander/corefx,pgavlin/corefx,Petermarcu/corefx,rahku/corefx,josguil/corefx,shahid-pk/corefx,cartermp/corefx,chenkennt/corefx,Yanjing123/corefx,heXelium/corefx,krk/corefx,stone-li/corefx,nbarbettini/corefx,vidhya-bv/corefx-sorting,huanjie/corefx,stormleoxia/corefx,dkorolev/corefx,the-dwyer/corefx,yizhang82/corefx,gabrielPeart/corefx,alexperovich/corefx,claudelee/corefx,iamjasonp/corefx,billwert/corefx,mafiya69/corefx,Ermiar/corefx,kkurni/corefx,pgavlin/corefx,uhaciogullari/corefx,shahid-pk/corefx,uhaciogullari/corefx,billwert/corefx,manu-silicon/corefx,mafiya69/corefx,Ermiar/corefx,brett25/corefx,benjamin-bader/corefx,nchikanov/corefx,SGuyGe/corefx,ericstj/corefx,Petermarcu/corefx,stormleoxia/corefx,huanjie/corefx,parjong/corefx,parjong/corefx,cartermp/corefx,PatrickMcDonald/corefx,the-dwyer/corefx,the-dwyer/corefx,parjong/corefx,akivafr123/corefx,dhoehna/corefx,heXelium/corefx,MaggieTsang/corefx,zhangwenquan/corefx,bitcrazed/corefx,elijah6/corefx,MaggieTsang/corefx,BrennanConroy/corefx,BrennanConroy/corefx,lggomez/corefx,cydhaselton/corefx,shimingsg/corefx,rubo/corefx,weltkante/corefx,mafiya69/corefx,seanshpark/corefx,ViktorHofer/corefx,dhoehna/corefx,josguil/corefx,seanshpark/corefx,nchikanov/corefx,fgreinacher/corefx,josguil/corefx,mokchhya/corefx,pgavlin/corefx,dsplaisted/corefx,janhenke/corefx,CherryCxldn/corefx,mazong1123/corefx,kkurni/corefx,shiftkey-tester/corefx,stephenmichaelf/corefx,690486439/corefx,richlander/corefx,vrassouli/corefx,vrassouli/corefx,stormleoxia/corefx,mmitche/corefx,chaitrakeshav/corefx,thiagodin/corefx,chaitrakeshav/corefx,gkhanna79/corefx,shmao/corefx,vs-team/corefx,rubo/corefx,Ermiar/corefx,chenxizhang/corefx,Priya91/corefx-1,billwert/corefx,the-dwyer/corefx,claudelee/corefx,cnbin/corefx,ravimeda/corefx,wtgodbe/corefx,marksmeltzer/corefx,jcme/corefx,benpye/corefx,the-dwyer/corefx,dotnet-bot/corefx,shimingsg/corefx,EverlessDrop41/corefx,jmhardison/corefx,jcme/corefx,pallavit/corefx,alexperovich/corefx,matthubin/corefx,Petermarcu/corefx,Ermiar/corefx,shmao/corefx,Yanjing123/corefx,ericstj/corefx,richlander/corefx,krk/corefx,heXelium/corefx,MaggieTsang/corefx,shmao/corefx,elijah6/corefx,misterzik/corefx,elijah6/corefx,bpschoch/corefx,mmitche/corefx,tstringer/corefx,dotnet-bot/corefx,yizhang82/corefx,CloudLens/corefx,benpye/corefx,janhenke/corefx,larsbj1988/corefx,benpye/corefx,billwert/corefx,ptoonen/corefx,mokchhya/corefx,bitcrazed/corefx,BrennanConroy/corefx,nbarbettini/corefx,anjumrizwi/corefx,khdang/corefx,mazong1123/corefx,krk/corefx,ptoonen/corefx,nchikanov/corefx,Petermarcu/corefx,manu-silicon/corefx,alexperovich/corefx,YoupHulsebos/corefx,jcme/corefx,mokchhya/corefx,uhaciogullari/corefx,alexandrnikitin/corefx,destinyclown/corefx,brett25/corefx,VPashkov/corefx,chenxizhang/corefx,shrutigarg/corefx,CloudLens/corefx,arronei/corefx,kyulee1/corefx,dtrebbien/corefx,spoiledsport/corefx,n1ghtmare/corefx,JosephTremoulet/corefx,Yanjing123/corefx,fffej/corefx,YoupHulsebos/corefx,oceanho/corefx,gkhanna79/corefx,Petermarcu/corefx,cartermp/corefx,bitcrazed/corefx,ViktorHofer/corefx,misterzik/corefx,cydhaselton/corefx,elijah6/corefx,mellinoe/corefx,Alcaro/corefx,ericstj/corefx,ViktorHofer/corefx,lydonchandra/corefx,shrutigarg/corefx,690486439/corefx,Jiayili1/corefx,n1ghtmare/corefx,zmaruo/corefx,mafiya69/corefx,dotnet-bot/corefx,YoupHulsebos/corefx,Priya91/corefx-1,fffej/corefx,yizhang82/corefx,Chrisboh/corefx,lydonchandra/corefx,mellinoe/corefx,scott156/corefx,fernando-rodriguez/corefx,shimingsg/corefx,alphonsekurian/corefx,tijoytom/corefx,krytarowski/corefx,zhangwenquan/corefx,khdang/corefx,Chrisboh/corefx,jhendrixMSFT/corefx,mafiya69/corefx,fffej/corefx,mmitche/corefx,andyhebear/corefx,VPashkov/corefx,DnlHarvey/corefx,zhenlan/corefx,richlander/corefx,Frank125/corefx,jhendrixMSFT/corefx,tijoytom/corefx,tstringer/corefx,s0ne0me/corefx,matthubin/corefx,KrisLee/corefx,manu-silicon/corefx,Ermiar/corefx,n1ghtmare/corefx,VPashkov/corefx,fffej/corefx,gkhanna79/corefx,shana/corefx,ellismg/corefx,JosephTremoulet/corefx,akivafr123/corefx,Alcaro/corefx,nchikanov/corefx,cydhaselton/corefx,alphonsekurian/corefx,jhendrixMSFT/corefx,alphonsekurian/corefx,weltkante/corefx,twsouthwick/corefx,xuweixuwei/corefx,the-dwyer/corefx,alphonsekurian/corefx,wtgodbe/corefx,rajansingh10/corefx,krk/corefx,weltkante/corefx,weltkante/corefx,yizhang82/corefx,rjxby/corefx,anjumrizwi/corefx,690486439/corefx,KrisLee/corefx,seanshpark/corefx,Frank125/corefx,weltkante/corefx,axelheer/corefx,arronei/corefx,Priya91/corefx-1,vidhya-bv/corefx-sorting,Jiayili1/corefx,dtrebbien/corefx,EverlessDrop41/corefx,vidhya-bv/corefx-sorting,benpye/corefx,Priya91/corefx-1,erpframework/corefx,dkorolev/corefx,gabrielPeart/corefx,twsouthwick/corefx,ravimeda/corefx,elijah6/corefx,ravimeda/corefx,pallavit/corefx,Jiayili1/corefx,thiagodin/corefx,vijaykota/corefx,ellismg/corefx,YoupHulsebos/corefx,stephenmichaelf/corefx,stephenmichaelf/corefx,alexperovich/corefx,shmao/corefx,adamralph/corefx,mmitche/corefx,shmao/corefx,stephenmichaelf/corefx,matthubin/corefx,billwert/corefx,fernando-rodriguez/corefx,n1ghtmare/corefx,rjxby/corefx,andyhebear/corefx,heXelium/corefx,jlin177/corefx,DnlHarvey/corefx,mokchhya/corefx,MaggieTsang/corefx,josguil/corefx,DnlHarvey/corefx,Priya91/corefx-1,Jiayili1/corefx,janhenke/corefx,alexandrnikitin/corefx,benpye/corefx,rubo/corefx,Winsto/corefx,chaitrakeshav/corefx,weltkante/corefx,VPashkov/corefx,ptoonen/corefx,parjong/corefx,comdiv/corefx,stephenmichaelf/corefx,huanjie/corefx,alexperovich/corefx,janhenke/corefx,gabrielPeart/corefx,lggomez/corefx,cnbin/corefx,rahku/corefx,wtgodbe/corefx,shimingsg/corefx,krk/corefx,nbarbettini/corefx,benjamin-bader/corefx,axelheer/corefx,richlander/corefx,zmaruo/corefx,cnbin/corefx,rajansingh10/corefx,ViktorHofer/corefx,marksmeltzer/corefx,pallavit/corefx,cydhaselton/corefx,kyulee1/corefx,rajansingh10/corefx,shana/corefx,gregg-miskelly/corefx,lggomez/corefx,shmao/corefx,shahid-pk/corefx,seanshpark/corefx,akivafr123/corefx,destinyclown/corefx,zhenlan/corefx,akivafr123/corefx,Yanjing123/corefx,jeremymeng/corefx,larsbj1988/corefx,scott156/corefx,dkorolev/corefx,rahku/corefx,rahku/corefx,nchikanov/corefx,parjong/corefx,pgavlin/corefx,mellinoe/corefx,lggomez/corefx,iamjasonp/corefx,krytarowski/corefx,jeremymeng/corefx,nelsonsar/corefx,wtgodbe/corefx,lggomez/corefx,MaggieTsang/corefx,ptoonen/corefx,Frank125/corefx,seanshpark/corefx,cydhaselton/corefx,dtrebbien/corefx,CloudLens/corefx,rahku/corefx,larsbj1988/corefx,mellinoe/corefx,wtgodbe/corefx