Add regression test for dotnet/coreclr#2531
Add regression test for dotnet/coreclr#2531

Ensure that en-US-POSIX does not get Turkish casing behavior.

YoupHulsebos/corefx,shahid-pk/corefx,axelheer/corefx,ravimeda/corefx,shimingsg/corefx,richlander/corefx,jlin177/corefx,mazong1123/corefx,DnlHarvey/corefx,josguil/corefx,dotnet-bot/corefx,weltkante/corefx,yizhang82/corefx,shimingsg/corefx,kkurni/corefx,JosephTremoulet/corefx,twsouthwick/corefx,stephenmichaelf/corefx,dotnet-bot/corefx,krk/corefx,axelheer/corefx,mokchhya/corefx,benpye/corefx,twsouthwick/corefx,MaggieTsang/corefx,rjxby/corefx,billwert/corefx,parjong/corefx,jcme/corefx,nchikanov/corefx,dhoehna/corefx,janhenke/corefx,dsplaisted/corefx,zhenlan/corefx,benjamin-bader/corefx,ellismg/corefx,mafiya69/corefx,DnlHarvey/corefx,mazong1123/corefx,wtgodbe/corefx,Ermiar/corefx,shahid-pk/corefx,twsouthwick/corefx,elijah6/corefx,ptoonen/corefx,dhoehna/corefx,parjong/corefx,nchikanov/corefx,mmitche/corefx,JosephTremoulet/corefx,jcme/corefx,Petermarcu/corefx,the-dwyer/corefx,Chrisboh/corefx,krytarowski/corefx,yizhang82/corefx,Petermarcu/corefx,DnlHarvey/corefx,shahid-pk/corefx,YoupHulsebos/corefx,benjamin-bader/corefx,iamjasonp/corefx,tijoytom/corefx,ViktorHofer/corefx,krytarowski/corefx,stone-li/corefx,kkurni/corefx,rjxby/corefx,seanshpark/corefx,Chrisboh/corefx,kkurni/corefx,jcme/corefx,rubo/corefx,elijah6/corefx,mmitche/corefx,dhoehna/corefx,axelheer/corefx,shahid-pk/corefx,rubo/corefx,alphonsekurian/corefx,cydhaselton/corefx,mokchhya/corefx,josguil/corefx,SGuyGe/corefx,stone-li/corefx,pallavit/corefx,JosephTremoulet/corefx,shahid-pk/corefx,khdang/corefx,Petermarcu/corefx,cartermp/corefx,tijoytom/corefx,wtgodbe/corefx,alexperovich/corefx,ericstj/corefx,krk/corefx,dotnet-bot/corefx,ericstj/corefx,jlin177/corefx,ellismg/corefx,tstringer/corefx,parjong/corefx,the-dwyer/corefx,Ermiar/corefx,the-dwyer/corefx,yizhang82/corefx,Petermarcu/corefx,Jiayili1/corefx,benpye/corefx,dsplaisted/corefx,axelheer/corefx,benpye/corefx,rjxby/corefx,tijoytom/corefx,mellinoe/corefx,gkhanna79/corefx,zhenlan/corefx,ViktorHofer/corefx,mellinoe/corefx,ericstj/corefx,cydhaselton/corefx,cartermp/corefx,krk/corefx,weltkante/corefx,alphonsekurian/corefx,rahku/corefx,jhendrixMSFT/corefx,cartermp/corefx,pallavit/corefx,alphonsekurian/corefx,ericstj/corefx,BrennanConroy/corefx,benpye/corefx,alexperovich/corefx,iamjasonp/corefx,jcme/corefx,krytarowski/corefx,iamjasonp/corefx,jlin177/corefx,MaggieTsang/corefx,DnlHarvey/corefx,tstringer/corefx,mafiya69/corefx,gkhanna79/corefx,YoupHulsebos/corefx,ravimeda/corefx,mokchhya/corefx,seanshpark/corefx,tijoytom/corefx,rahku/corefx,YoupHulsebos/corefx,ellismg/corefx,nbarbettini/corefx,jhendrixMSFT/corefx,lggomez/corefx,yizhang82/corefx,nchikanov/corefx,seanshpark/corefx,MaggieTsang/corefx,marksmeltzer/corefx,richlander/corefx,shmao/corefx,billwert/corefx,MaggieTsang/corefx,dhoehna/corefx,stone-li/corefx,shmao/corefx,janhenke/corefx,stone-li/corefx,nbarbettini/corefx,richlander/corefx,mokchhya/corefx,Priya91/corefx-1,lggomez/corefx,tstringer/corefx,cydhaselton/corefx,axelheer/corefx,rubo/corefx,zhenlan/corefx,janhenke/corefx,JosephTremoulet/corefx,parjong/corefx,mellinoe/corefx,Priya91/corefx-1,dhoehna/corefx,jlin177/corefx,shmao/corefx,pallavit/corefx,richlander/corefx,Ermiar/corefx,tstringer/corefx,alexperovich/corefx,mokchhya/corefx,shimingsg/corefx,lggomez/corefx,axelheer/corefx,gkhanna79/corefx,yizhang82/corefx,shimingsg/corefx,mazong1123/corefx,fgreinacher/corefx,seanshpark/corefx,gkhanna79/corefx,Priya91/corefx-1,jhendrixMSFT/corefx,tstringer/corefx,jcme/corefx,Jiayili1/corefx,DnlHarvey/corefx,stephenmichaelf/corefx,the-dwyer/corefx,ptoonen/corefx,mazong1123/corefx,dotnet-bot/corefx,elijah6/corefx,JosephTremoulet/corefx,manu-silicon/corefx,the-dwyer/corefx,manu-silicon/corefx,dotnet-bot/corefx,alphonsekurian/corefx,ericstj/corefx,nchikanov/corefx,SGuyGe/corefx,stephenmichaelf/corefx,parjong/corefx,dotnet-bot/corefx,lggomez/corefx,weltkante/corefx,benjamin-bader/corefx,SGuyGe/corefx,cartermp/corefx,Chrisboh/corefx,yizhang82/corefx,rjxby/corefx,marksmeltzer/corefx,jhendrixMSFT/corefx,ellismg/corefx,ellismg/corefx,YoupHulsebos/corefx,manu-silicon/corefx,krk/corefx,dhoehna/corefx,mazong1123/corefx,marksmeltzer/corefx,DnlHarvey/corefx,shmao/corefx,stone-li/corefx,Petermarcu/corefx,ptoonen/corefx,zhenlan/corefx,cartermp/corefx,Ermiar/corefx,janhenke/corefx,josguil/corefx,stephenmichaelf/corefx,krytarowski/corefx,mmitche/corefx,adamralph/corefx,parjong/corefx,shahid-pk/corefx,Jiayili1/corefx,alexperovich/corefx,elijah6/corefx,manu-silicon/corefx,billwert/corefx,josguil/corefx,billwert/corefx,Jiayili1/corefx,manu-silicon/corefx,Jiayili1/corefx,stone-li/corefx,gkhanna79/corefx,wtgodbe/corefx,twsouthwick/corefx,rahku/corefx,rahku/corefx,nbarbettini/corefx,fgreinacher/corefx,BrennanConroy/corefx,shmao/corefx,ViktorHofer/corefx,shimingsg/corefx,kkurni/corefx,weltkante/corefx,JosephTremoulet/corefx,MaggieTsang/corefx,MaggieTsang/corefx,benjamin-bader/corefx,twsouthwick/corefx,tstringer/corefx,stephenmichaelf/corefx,ravimeda/corefx,cartermp/corefx,benpye/corefx,khdang/corefx,marksmeltzer/corefx,alphonsekurian/corefx,mokchhya/corefx,wtgodbe/corefx,Ermiar/corefx,parjong/corefx,seanshpark/corefx,dsplaisted/corefx,cydhaselton/corefx,twsouthwick/corefx,ravimeda/corefx,marksmeltzer/corefx,rahku/corefx,elijah6/corefx,khdang/corefx,elijah6/corefx,tijoytom/corefx,Chrisboh/corefx,shimingsg/corefx,Priya91/corefx-1,alphonsekurian/corefx,ravimeda/corefx,tijoytom/corefx,mazong1123/corefx,Chrisboh/corefx,janhenke/corefx,benjamin-bader/corefx,weltkante/corefx,manu-silicon/corefx,nbarbettini/corefx,iamjasonp/corefx,cydhaselton/corefx,jlin177/corefx,billwert/corefx,nchikanov/corefx,Priya91/corefx-1,ravimeda/corefx,rjxby/corefx,mmitche/corefx,Priya91/corefx-1,stephenmichaelf/corefx,krk/corefx,richlander/corefx,pallavit/corefx,mellinoe/corefx,the-dwyer/corefx,wtgodbe/corefx,gkhanna79/corefx,zhenlan/corefx,lggomez/corefx,zhenlan/corefx,ericstj/corefx,elijah6/corefx,Petermarcu/corefx,Petermarcu/corefx,alexperovich/corefx,shimingsg/corefx,benpye/corefx,mazong1123/corefx,khdang/corefx,mafiya69/corefx,pallavit/corefx,rahku/corefx,alphonsekurian/corefx,seanshpark/corefx,rubo/corefx,kkurni/corefx,jhendrixMSFT/corefx,iamjasonp/corefx,nbarbettini/corefx,jlin177/corefx,zhenlan/corefx,ViktorHofer/corefx,shmao/corefx,krytarowski/corefx,mellinoe/corefx,stephenmichaelf/corefx,dhoehna/corefx,Chrisboh/corefx,cydhaselton/corefx,adamralph/corefx,rahku/corefx,JosephTremoulet/corefx,SGuyGe/corefx,MaggieTsang/corefx,weltkante/corefx,stone-li/corefx,iamjasonp/corefx,lggomez/corefx,mmitche/corefx,weltkante/corefx,jlin177/corefx,YoupHulsebos/corefx,YoupHulsebos/corefx,lggomez/corefx,benjamin-bader/corefx,janhenke/corefx,kkurni/corefx,gkhanna79/corefx,rjxby/corefx,wtgodbe/corefx,marksmeltzer/corefx,jcme/corefx,jhendrixMSFT/corefx,nbarbettini/corefx,pallavit/corefx,krytarowski/corefx,Jiayili1/corefx,krk/corefx,krk/corefx,seanshpark/corefx,ViktorHofer/corefx,mmitche/corefx,khdang/corefx,billwert/corefx,richlander/corefx,ptoonen/corefx,ptoonen/corefx,yizhang82/corefx,khdang/corefx,nbarbettini/corefx,Jiayili1/corefx,ViktorHofer/corefx,josguil/corefx,richlander/corefx,ellismg/corefx,alexperovich/corefx,ptoonen/corefx,iamjasonp/corefx,wtgodbe/corefx,nchikanov/corefx,adamralph/corefx,alexperovich/corefx,nchikanov/corefx,ericstj/corefx,mafiya69/corefx,billwert/corefx,josguil/corefx,DnlHarvey/corefx,cydhaselton/corefx,Ermiar/corefx,fgreinacher/corefx,mafiya69/corefx,Ermiar/corefx,krytarowski/corefx,rjxby/corefx,manu-silicon/corefx,twsouthwick/corefx,ViktorHofer/corefx,mafiya69/corefx,ravimeda/corefx,BrennanConroy/corefx,rubo/corefx,shmao/corefx,dotnet-bot/corefx,tijoytom/corefx,ptoonen/corefx,SGuyGe/corefx,mmitche/corefx,fgreinacher/corefx,the-dwyer/corefx,mellinoe/corefx,marksmeltzer/corefx,jhendrixMSFT/corefx,SGuyGe/corefx