Fix stack unwinding for FreeBSD.
Fix stack unwinding for FreeBSD.

Fix error in stack unwinding on FreeBSD as discovered by @saper.

This closes #1102 and #1113

dkorolev/coreclr,schellap/coreclr,fernando-rodriguez/coreclr,ericeil/coreclr,bartdesmet/coreclr,blackdwarf/coreclr,misterzik/coreclr,wkchoy74/coreclr,GuilhermeSa/coreclr,AlexGhiondea/coreclr,taylorjonl/coreclr,poizan42/coreclr,xtypebee/coreclr,wkchoy74/coreclr,geertdoornbos/coreclr,bjjones/coreclr,ericeil/coreclr,sagood/coreclr,ragmani/coreclr,cmckinsey/coreclr,MCGPPeters/coreclr,ktos/coreclr,dasMulli/coreclr,krixalis/coreclr,AlexGhiondea/coreclr,bartonjs/coreclr,cydhaselton/coreclr,benpye/coreclr,cydhaselton/coreclr,mskvortsov/coreclr,ganeshran/coreclr,martinwoodward/coreclr,bjjones/coreclr,dkorolev/coreclr,yeaicc/coreclr,James-Ko/coreclr,KrzysztofCwalina/coreclr,sergey-raevskiy/coreclr,krk/coreclr,gkhanna79/coreclr,KrzysztofCwalina/coreclr,ramarag/coreclr,Dmitry-Me/coreclr,gitchomik/coreclr,hanu412/coreclr,mokchhya/coreclr,Djuffin/coreclr,ramarag/coreclr,bartonjs/coreclr,mskvortsov/coreclr,Godin/coreclr,vinnyrom/coreclr,manu-silicon/coreclr,alexperovich/coreclr,stormleoxia/coreclr,ktos/coreclr,yizhang82/coreclr,krytarowski/coreclr,jhendrixMSFT/coreclr,James-Ko/coreclr,xtypebee/coreclr,xoofx/coreclr,grokys/coreclr,Dmitry-Me/coreclr,wateret/coreclr,bitcrazed/coreclr,Lucrecious/coreclr,krk/coreclr,SlavaRa/coreclr,tijoytom/coreclr,iamjasonp/coreclr,ragmani/coreclr,jamesqo/coreclr,xtypebee/coreclr,SpotLabsNET/coreclr,blackdwarf/coreclr,botaberg/coreclr,gitchomik/coreclr,mokchhya/coreclr,LLITCHEV/coreclr,fernando-rodriguez/coreclr,ganeshran/coreclr,martinwoodward/coreclr,yizhang82/coreclr,ktos/coreclr,YongseopKim/coreclr,fffej/coreclr,wtgodbe/coreclr,yeaicc/coreclr,ytechie/coreclr,gkhanna79/coreclr,krytarowski/coreclr,qiudesong/coreclr,ragmani/coreclr,cshung/coreclr,Sridhar-MS/coreclr,poizan42/coreclr,lzcj4/coreclr,JosephTremoulet/coreclr,wtgodbe/coreclr,kyulee1/coreclr,stormleoxia/coreclr,geertdoornbos/coreclr,SpotLabsNET/coreclr,zmaruo/coreclr,sperling/coreclr,parjong/coreclr,hseok-oh/coreclr,shahid-pk/coreclr,KrzysztofCwalina/coreclr,russellhadley/coreclr,ktos/coreclr,andschwa/coreclr,alexperovich/coreclr,jamesqo/coreclr,parjong/coreclr,mmitche/coreclr,apanda/coreclr,chuck-mitchell/coreclr,bartonjs/coreclr,tijoytom/coreclr,bartonjs/coreclr,wateret/coreclr,cydhaselton/coreclr,swgillespie/coreclr,MCGPPeters/coreclr,blackdwarf/coreclr,roncain/coreclr,dkorolev/coreclr,sergey-raevskiy/coreclr,lzcj4/coreclr,Dmitry-Me/coreclr,josteink/coreclr,bjjones/coreclr,shahid-pk/coreclr,blackdwarf/coreclr,fffej/coreclr,KrzysztofCwalina/coreclr,mokchhya/coreclr,dkorolev/coreclr,shahid-pk/coreclr,neurospeech/coreclr,James-Ko/coreclr,dasMulli/coreclr,botaberg/coreclr,wtgodbe/coreclr,russellhadley/coreclr,James-Ko/coreclr,serenabenny/coreclr,JosephTremoulet/coreclr,ZhichengZhu/coreclr,AlexGhiondea/coreclr,bjjones/coreclr,roncain/coreclr,Samana/coreclr,serenabenny/coreclr,david-mitchell/coreclr,yizhang82/coreclr,sagood/coreclr,misterzik/coreclr,Sridhar-MS/coreclr,mskvortsov/coreclr,wkchoy74/coreclr,naamunds/coreclr,orthoxerox/coreclr,grokys/coreclr,matthubin/coreclr,wkchoy74/coreclr,JosephTremoulet/coreclr,AlfredoMS/coreclr,qiudesong/coreclr,SlavaRa/coreclr,sergey-raevskiy/coreclr,bartonjs/coreclr,benpye/coreclr,tijoytom/coreclr,wateret/coreclr,AlexGhiondea/coreclr,vinnyrom/coreclr,jhendrixMSFT/coreclr,mmitche/coreclr,sergey-raevskiy/coreclr,parjong/coreclr,yeaicc/coreclr,manu-silicon/coreclr,stormleoxia/coreclr,hanu412/coreclr,AlfredoMS/coreclr,misterzik/coreclr,Lucrecious/coreclr,geertdoornbos/coreclr,botaberg/coreclr,James-Ko/coreclr,perfectphase/coreclr,gitchomik/coreclr,krixalis/coreclr,ericeil/coreclr,ytechie/coreclr,apanda/coreclr,ruben-ayrapetyan/coreclr,chrishaly/coreclr,DasAllFolks/coreclr,jhendrixMSFT/coreclr,ZhichengZhu/coreclr,matthubin/coreclr,vinnyrom/coreclr,cshung/coreclr,hanu412/coreclr,chuck-mitchell/coreclr,andschwa/coreclr,josteink/coreclr,geertdoornbos/coreclr,pgavlin/coreclr,Djuffin/coreclr,sejongoh/coreclr,xtypebee/coreclr,sagood/coreclr,gitchomik/coreclr,stormleoxia/coreclr,chuck-mitchell/coreclr,bitcrazed/coreclr,josteink/coreclr,alexperovich/coreclr,MCGPPeters/coreclr,Alcaro/coreclr,david-mitchell/coreclr,chuck-mitchell/coreclr,swgillespie/coreclr,JonHanna/coreclr,DasAllFolks/coreclr,jhendrixMSFT/coreclr,chuck-mitchell/coreclr,SpotLabsNET/coreclr,misterzik/coreclr,ZhichengZhu/coreclr,ericeil/coreclr,krixalis/coreclr,dpodder/coreclr,YongseopKim/coreclr,sperling/coreclr,wateret/coreclr,cydhaselton/coreclr,iamjasonp/coreclr,wtgodbe/coreclr,YongseopKim/coreclr,apanda/coreclr,AlexGhiondea/coreclr,gkhanna79/coreclr,JosephTremoulet/coreclr,yeaicc/coreclr,zmaruo/coreclr,orthoxerox/coreclr,dkorolev/coreclr,OryJuVog/coreclr,DasAllFolks/coreclr,Djuffin/coreclr,wkchoy74/coreclr,wtgodbe/coreclr,Djuffin/coreclr,LLITCHEV/coreclr,ktos/coreclr,mocsy/coreclr,stormleoxia/coreclr,orthoxerox/coreclr,gkhanna79/coreclr,roncain/coreclr,taylorjonl/coreclr,dasMulli/coreclr,MCGPPeters/coreclr,mocsy/coreclr,serenabenny/coreclr,Dmitry-Me/coreclr,sergey-raevskiy/coreclr,chaos7theory/coreclr,rartemev/coreclr,Alcaro/coreclr,lzcj4/coreclr,blackdwarf/coreclr,chuck-mitchell/coreclr,cshung/coreclr,chaos7theory/coreclr,hseok-oh/coreclr,Alcaro/coreclr,bartdesmet/coreclr,AlfredoMS/coreclr,bartdesmet/coreclr,ytechie/coreclr,yizhang82/coreclr,fernando-rodriguez/coreclr,martinwoodward/coreclr,misterzik/coreclr,gitchomik/coreclr,roncain/coreclr,chaos7theory/coreclr,orthoxerox/coreclr,wateret/coreclr,xtypebee/coreclr,shahid-pk/coreclr,sergey-raevskiy/coreclr,cmckinsey/coreclr,andschwa/coreclr,matthubin/coreclr,cmckinsey/coreclr,fffej/coreclr,krk/coreclr,sagood/coreclr,ragmani/coreclr,grokys/coreclr,serenabenny/coreclr,shahid-pk/coreclr,fernando-rodriguez/coreclr,perfectphase/coreclr,pgavlin/coreclr,GuilhermeSa/coreclr,xtypebee/coreclr,tijoytom/coreclr,iamjasonp/coreclr,dasMulli/coreclr,dpodder/coreclr,JonHanna/coreclr,dpodder/coreclr,SlavaRa/coreclr,Dmitry-Me/coreclr,SpotLabsNET/coreclr,Sridhar-MS/coreclr,rartemev/coreclr,Alcaro/coreclr,dasMulli/coreclr,cydhaselton/coreclr,grokys/coreclr,KrzysztofCwalina/coreclr,dpodder/coreclr,sperling/coreclr,JonHanna/coreclr,sperling/coreclr,kyulee1/coreclr,matthubin/coreclr,lzcj4/coreclr,schellap/coreclr,dasMulli/coreclr,swgillespie/coreclr,krixalis/coreclr,schellap/coreclr,AlfredoMS/coreclr,Dmitry-Me/coreclr,sjsinju/coreclr,manu-silicon/coreclr,naamunds/coreclr,mskvortsov/coreclr,hseok-oh/coreclr,naamunds/coreclr,sejongoh/coreclr,ZhichengZhu/coreclr,martinwoodward/coreclr,mokchhya/coreclr,sejongoh/coreclr,ramarag/coreclr,ramarag/coreclr,bjjones/coreclr,apanda/coreclr,LLITCHEV/coreclr,ruben-ayrapetyan/coreclr,chaos7theory/coreclr,bitcrazed/coreclr,JosephTremoulet/coreclr,vinnyrom/coreclr,chrishaly/coreclr,krytarowski/coreclr,parjong/coreclr,geertdoornbos/coreclr,mmitche/coreclr,andschwa/coreclr,SlavaRa/coreclr,dasMulli/coreclr,iamjasonp/coreclr,sjsinju/coreclr,yeaicc/coreclr,AlexGhiondea/coreclr,iamjasonp/coreclr,Samana/coreclr,chuck-mitchell/coreclr,Lucrecious/coreclr,ramarag/coreclr,ganeshran/coreclr,roncain/coreclr,benpye/coreclr,fffej/coreclr,mmitche/coreclr,bitcrazed/coreclr,bitcrazed/coreclr,geertdoornbos/coreclr,ruben-ayrapetyan/coreclr,fffej/coreclr,ericeil/coreclr,fernando-rodriguez/coreclr,OryJuVog/coreclr,perfectphase/coreclr,stormleoxia/coreclr,Godin/coreclr,swgillespie/coreclr,neurospeech/coreclr,kyulee1/coreclr,martinwoodward/coreclr,Djuffin/coreclr,chaos7theory/coreclr,YongseopKim/coreclr,LLITCHEV/coreclr,mocsy/coreclr,cmckinsey/coreclr,yeaicc/coreclr,mocsy/coreclr,kyulee1/coreclr,krk/coreclr,qiudesong/coreclr,sperling/coreclr,qiudesong/coreclr,Godin/coreclr,serenabenny/coreclr,OryJuVog/coreclr,tijoytom/coreclr,ytechie/coreclr,poizan42/coreclr,bitcrazed/coreclr,mocsy/coreclr,naamunds/coreclr,wkchoy74/coreclr,KrzysztofCwalina/coreclr,hseok-oh/coreclr,alexperovich/coreclr,ZhichengZhu/coreclr,OryJuVog/coreclr,Godin/coreclr,ruben-ayrapetyan/coreclr,josteink/coreclr,Sridhar-MS/coreclr,lzcj4/coreclr,schellap/coreclr,mmitche/coreclr,russellhadley/coreclr,DasAllFolks/coreclr,mskvortsov/coreclr,mokchhya/coreclr,LLITCHEV/coreclr,zmaruo/coreclr,matthubin/coreclr,ramarag/coreclr,pgavlin/coreclr,mokchhya/coreclr,perfectphase/coreclr,cshung/coreclr,parjong/coreclr,poizan42/coreclr,parjong/coreclr,ragmani/coreclr,sperling/coreclr,schellap/coreclr,DasAllFolks/coreclr,wtgodbe/coreclr,xoofx/coreclr,fffej/coreclr,grokys/coreclr,yizhang82/coreclr,Alcaro/coreclr,GuilhermeSa/coreclr,ZhichengZhu/coreclr,josteink/coreclr,Samana/coreclr,cmckinsey/coreclr,JosephTremoulet/coreclr,vinnyrom/coreclr,MCGPPeters/coreclr,krk/coreclr,SpotLabsNET/coreclr,naamunds/coreclr,krixalis/coreclr,cmckinsey/coreclr,cshung/coreclr,neurospeech/coreclr,roncain/coreclr,yeaicc/coreclr,jamesqo/coreclr,jhendrixMSFT/coreclr,sejongoh/coreclr,Sridhar-MS/coreclr,russellhadley/coreclr,manu-silicon/coreclr,ZhichengZhu/coreclr,sagood/coreclr,andschwa/coreclr,stormleoxia/coreclr,GuilhermeSa/coreclr,ramarag/coreclr,sjsinju/coreclr,fernando-rodriguez/coreclr,manu-silicon/coreclr,JonHanna/coreclr,JonHanna/coreclr,SpotLabsNET/coreclr,hanu412/coreclr,alexperovich/coreclr,hanu412/coreclr,ytechie/coreclr,James-Ko/coreclr,jhendrixMSFT/coreclr,MCGPPeters/coreclr,Samana/coreclr,chaos7theory/coreclr,benpye/coreclr,xoofx/coreclr,krk/coreclr,roncain/coreclr,Lucrecious/coreclr,orthoxerox/coreclr,xoofx/coreclr,wkchoy74/coreclr,alexperovich/coreclr,qiudesong/coreclr,cmckinsey/coreclr,krixalis/coreclr,Samana/coreclr,zmaruo/coreclr,poizan42/coreclr,bartonjs/coreclr,bartonjs/coreclr,pgavlin/coreclr,xoofx/coreclr,apanda/coreclr,taylorjonl/coreclr,Lucrecious/coreclr,GuilhermeSa/coreclr,gitchomik/coreclr,poizan42/coreclr,tijoytom/coreclr,bjjones/coreclr,shana/coreclr,pgavlin/coreclr,sejongoh/coreclr,misterzik/coreclr,jamesqo/coreclr,shana/coreclr,chrishaly/coreclr,kyulee1/coreclr,iamjasonp/coreclr,krytarowski/coreclr,cshung/coreclr,ganeshran/coreclr,hseok-oh/coreclr,gkhanna79/coreclr,ericeil/coreclr,dkorolev/coreclr,taylorjonl/coreclr,kyulee1/coreclr,botaberg/coreclr,rartemev/coreclr,dpodder/coreclr,KrzysztofCwalina/coreclr,shahid-pk/coreclr,benpye/coreclr,rartemev/coreclr,rartemev/coreclr,wateret/coreclr,Godin/coreclr,andschwa/coreclr,manu-silicon/coreclr,ganeshran/coreclr,Lucrecious/coreclr,shana/coreclr,mocsy/coreclr,jamesqo/coreclr,bitcrazed/coreclr,martinwoodward/coreclr,russellhadley/coreclr,botaberg/coreclr,neurospeech/coreclr,vinnyrom/coreclr,qiudesong/coreclr,jamesqo/coreclr,Sridhar-MS/coreclr,SlavaRa/coreclr,neurospeech/coreclr,Godin/coreclr,LLITCHEV/coreclr,blackdwarf/coreclr,vinnyrom/coreclr,perfectphase/coreclr,shahid-pk/coreclr,YongseopKim/coreclr,JonHanna/coreclr,benpye/coreclr,ruben-ayrapetyan/coreclr,david-mitchell/coreclr,Lucrecious/coreclr,ytechie/coreclr,zmaruo/coreclr,matthubin/coreclr,botaberg/coreclr,martinwoodward/coreclr,josteink/coreclr,lzcj4/coreclr,geertdoornbos/coreclr,jhendrixMSFT/coreclr,cydhaselton/coreclr,schellap/coreclr,naamunds/coreclr,bartdesmet/coreclr,sperling/coreclr,ktos/coreclr,shana/coreclr,swgillespie/coreclr,pgavlin/coreclr,hanu412/coreclr,swgillespie/coreclr,andschwa/coreclr,schellap/coreclr,taylorjonl/coreclr,sejongoh/coreclr,shana/coreclr,shana/coreclr,YongseopKim/coreclr,taylorjonl/coreclr,russellhadley/coreclr,OryJuVog/coreclr,Djuffin/coreclr,sejongoh/coreclr,AlfredoMS/coreclr,hseok-oh/coreclr,chrishaly/coreclr,sjsinju/coreclr,sjsinju/coreclr,mmitche/coreclr,blackdwarf/coreclr,mskvortsov/coreclr,ragmani/coreclr,grokys/coreclr,david-mitchell/coreclr,perfectphase/coreclr,apanda/coreclr,Alcaro/coreclr,naamunds/coreclr,Samana/coreclr,bartdesmet/coreclr,LLITCHEV/coreclr,benpye/coreclr,ruben-ayrapetyan/coreclr,SlavaRa/coreclr,david-mitchell/coreclr,sagood/coreclr,serenabenny/coreclr,AlfredoMS/coreclr,gkhanna79/coreclr,ktos/coreclr,josteink/coreclr,xoofx/coreclr,bartdesmet/coreclr,neurospeech/coreclr,taylorjonl/coreclr,zmaruo/coreclr,yizhang82/coreclr,GuilhermeSa/coreclr,Godin/coreclr,Dmitry-Me/coreclr,OryJuVog/coreclr,chrishaly/coreclr,manu-silicon/coreclr,rartemev/coreclr,mokchhya/coreclr,sjsinju/coreclr,swgillespie/coreclr,orthoxerox/coreclr,ganeshran/coreclr,dpodder/coreclr,krytarowski/coreclr,chrishaly/coreclr,david-mitchell/coreclr,DasAllFolks/coreclr,mocsy/coreclr,bartdesmet/coreclr,krytarowski/coreclr