Fix NetBSD build: Define virtual destructors when needed
Fix NetBSD build: Define virtual destructors when needed

This fixes the following error with recent Clang (3.9.0nb20160205):

In file included from /tmp/pkgsrc-tmp/wip/coreclr-git/work/coreclr/src/pal/src/synchmgr/synchcontrollers.cpp:20:
In file included from /tmp/pkgsrc-tmp/wip/coreclr-git/work/coreclr/src/pal/src/synchmgr/synchmanager.hpp:24:
/tmp/pkgsrc-tmp/wip/coreclr-git/work/coreclr/src/pal/src/include/pal/synchcache.hpp:146:13: error: destructor called on non-final 'CorUnix::CSynchWaitController' that has virtual functions but non-virtual destructor [-Werror,-Wdelete-non-virtual-dtor]
            pobj->~T();
            ^
/tmp/pkgsrc-tmp/wip/coreclr-git/work/coreclr/src/pal/src/synchmgr/synchmanager.hpp:724:31: note: in instantiation of member function 'CorUnix::CSynchCache<CorUnix::CSynchWaitController>::Add' requested here
            m_cacheWaitCtrlrs.Add(pthrCurrent, pCtrlr);
                              ^
/tmp/pkgsrc-tmp/wip/coreclr-git/work/coreclr/src/pal/src/include/pal/synchcache.hpp:146:20: note: qualify call to silence this warning
            pobj->~T();
                   ^
                   CorUnix::CSynchWaitController::
/tmp/pkgsrc-tmp/wip/coreclr-git/work/coreclr/src/pal/src/include/pal/synchcache.hpp:146:13: error: destructor called on non-final 'CorUnix::CSynchStateController' that has virtual functions but non-virtual destructor [-Werror,-Wdelete-non-virtual-dtor]
            pobj->~T();
            ^
/tmp/pkgsrc-tmp/wip/coreclr-git/work/coreclr/src/pal/src/synchmgr/synchmanager.hpp:741:32: note: in instantiation of member function 'CorUnix::CSynchCache<CorUnix::CSynchStateController>::Add' requested here
            m_cacheStateCtrlrs.Add(pthrCurrent, pCtrlr);
                               ^
/tmp/pkgsrc-tmp/wip/coreclr-git/work/coreclr/src/pal/src/include/pal/synchcache.hpp:146:20: note: qualify call to silence this warning
            pobj->~T();
                   ^
                   CorUnix::CSynchStateController::
2 errors generated.

tijoytom/coreclr,James-Ko/coreclr,KrzysztofCwalina/coreclr,qiudesong/coreclr,martinwoodward/coreclr,naamunds/coreclr,vinnyrom/coreclr,alexperovich/coreclr,kyulee1/coreclr,vinnyrom/coreclr,hseok-oh/coreclr,sjsinju/coreclr,josteink/coreclr,dpodder/coreclr,krk/coreclr,ramarag/coreclr,KrzysztofCwalina/coreclr,botaberg/coreclr,russellhadley/coreclr,neurospeech/coreclr,Godin/coreclr,sagood/coreclr,jamesqo/coreclr,sperling/coreclr,qiudesong/coreclr,naamunds/coreclr,russellhadley/coreclr,schellap/coreclr,rartemev/coreclr,botaberg/coreclr,poizan42/coreclr,wtgodbe/coreclr,jhendrixMSFT/coreclr,ruben-ayrapetyan/coreclr,Lucrecious/coreclr,andschwa/coreclr,alexperovich/coreclr,Dmitry-Me/coreclr,rartemev/coreclr,mmitche/coreclr,YongseopKim/coreclr,rartemev/coreclr,ramarag/coreclr,KrzysztofCwalina/coreclr,krytarowski/coreclr,swgillespie/coreclr,krk/coreclr,shahid-pk/coreclr,qiudesong/coreclr,bartonjs/coreclr,wtgodbe/coreclr,Lucrecious/coreclr,parjong/coreclr,wkchoy74/coreclr,wkchoy74/coreclr,pgavlin/coreclr,ZhichengZhu/coreclr,andschwa/coreclr,wateret/coreclr,qiudesong/coreclr,russellhadley/coreclr,LLITCHEV/coreclr,gkhanna79/coreclr,bartdesmet/coreclr,dpodder/coreclr,James-Ko/coreclr,ZhichengZhu/coreclr,LLITCHEV/coreclr,SlavaRa/coreclr,JosephTremoulet/coreclr,bartdesmet/coreclr,cshung/coreclr,sjsinju/coreclr,James-Ko/coreclr,benpye/coreclr,neurospeech/coreclr,LLITCHEV/coreclr,gkhanna79/coreclr,rartemev/coreclr,JonHanna/coreclr,yizhang82/coreclr,alexperovich/coreclr,sagood/coreclr,ragmani/coreclr,bartdesmet/coreclr,bartonjs/coreclr,bartonjs/coreclr,sperling/coreclr,ZhichengZhu/coreclr,JosephTremoulet/coreclr,sagood/coreclr,mokchhya/coreclr,schellap/coreclr,wateret/coreclr,josteink/coreclr,Godin/coreclr,sejongoh/coreclr,YongseopKim/coreclr,roncain/coreclr,schellap/coreclr,manu-silicon/coreclr,cydhaselton/coreclr,chuck-mitchell/coreclr,mokchhya/coreclr,ragmani/coreclr,ZhichengZhu/coreclr,roncain/coreclr,sejongoh/coreclr,wkchoy74/coreclr,vinnyrom/coreclr,jhendrixMSFT/coreclr,martinwoodward/coreclr,shahid-pk/coreclr,wkchoy74/coreclr,swgillespie/coreclr,botaberg/coreclr,ragmani/coreclr,yizhang82/coreclr,Lucrecious/coreclr,bartonjs/coreclr,sejongoh/coreclr,cshung/coreclr,sejongoh/coreclr,JonHanna/coreclr,mokchhya/coreclr,vinnyrom/coreclr,mokchhya/coreclr,YongseopKim/coreclr,LLITCHEV/coreclr,SlavaRa/coreclr,poizan42/coreclr,cydhaselton/coreclr,tijoytom/coreclr,chuck-mitchell/coreclr,jhendrixMSFT/coreclr,schellap/coreclr,Godin/coreclr,naamunds/coreclr,andschwa/coreclr,benpye/coreclr,manu-silicon/coreclr,mmitche/coreclr,naamunds/coreclr,AlexGhiondea/coreclr,James-Ko/coreclr,sjsinju/coreclr,benpye/coreclr,ramarag/coreclr,SlavaRa/coreclr,andschwa/coreclr,josteink/coreclr,ruben-ayrapetyan/coreclr,KrzysztofCwalina/coreclr,rartemev/coreclr,cshung/coreclr,mmitche/coreclr,cmckinsey/coreclr,dpodder/coreclr,josteink/coreclr,sjsinju/coreclr,cshung/coreclr,KrzysztofCwalina/coreclr,sperling/coreclr,alexperovich/coreclr,chuck-mitchell/coreclr,swgillespie/coreclr,ruben-ayrapetyan/coreclr,kyulee1/coreclr,krk/coreclr,yeaicc/coreclr,dpodder/coreclr,jamesqo/coreclr,cmckinsey/coreclr,hseok-oh/coreclr,parjong/coreclr,jamesqo/coreclr,yeaicc/coreclr,bartonjs/coreclr,hseok-oh/coreclr,LLITCHEV/coreclr,roncain/coreclr,cmckinsey/coreclr,bartonjs/coreclr,manu-silicon/coreclr,dasMulli/coreclr,James-Ko/coreclr,josteink/coreclr,botaberg/coreclr,botaberg/coreclr,mskvortsov/coreclr,cshung/coreclr,dasMulli/coreclr,Dmitry-Me/coreclr,AlexGhiondea/coreclr,jamesqo/coreclr,Lucrecious/coreclr,cmckinsey/coreclr,kyulee1/coreclr,tijoytom/coreclr,manu-silicon/coreclr,Lucrecious/coreclr,tijoytom/coreclr,ragmani/coreclr,vinnyrom/coreclr,chuck-mitchell/coreclr,yizhang82/coreclr,ramarag/coreclr,josteink/coreclr,dpodder/coreclr,jhendrixMSFT/coreclr,hseok-oh/coreclr,vinnyrom/coreclr,ZhichengZhu/coreclr,krytarowski/coreclr,gkhanna79/coreclr,James-Ko/coreclr,parjong/coreclr,KrzysztofCwalina/coreclr,JosephTremoulet/coreclr,krytarowski/coreclr,ragmani/coreclr,LLITCHEV/coreclr,Dmitry-Me/coreclr,yeaicc/coreclr,mskvortsov/coreclr,ZhichengZhu/coreclr,mokchhya/coreclr,Lucrecious/coreclr,mocsy/coreclr,yeaicc/coreclr,JosephTremoulet/coreclr,pgavlin/coreclr,gkhanna79/coreclr,poizan42/coreclr,LLITCHEV/coreclr,Godin/coreclr,jhendrixMSFT/coreclr,bartdesmet/coreclr,bartdesmet/coreclr,krk/coreclr,Godin/coreclr,dasMulli/coreclr,ZhichengZhu/coreclr,SlavaRa/coreclr,tijoytom/coreclr,YongseopKim/coreclr,hseok-oh/coreclr,chuck-mitchell/coreclr,KrzysztofCwalina/coreclr,sjsinju/coreclr,Lucrecious/coreclr,botaberg/coreclr,dasMulli/coreclr,mocsy/coreclr,mokchhya/coreclr,wtgodbe/coreclr,sejongoh/coreclr,bartdesmet/coreclr,cshung/coreclr,pgavlin/coreclr,martinwoodward/coreclr,shahid-pk/coreclr,sperling/coreclr,YongseopKim/coreclr,gkhanna79/coreclr,chuck-mitchell/coreclr,sejongoh/coreclr,JonHanna/coreclr,kyulee1/coreclr,wtgodbe/coreclr,krytarowski/coreclr,ragmani/coreclr,parjong/coreclr,JosephTremoulet/coreclr,wkchoy74/coreclr,alexperovich/coreclr,parjong/coreclr,russellhadley/coreclr,wateret/coreclr,sagood/coreclr,vinnyrom/coreclr,Godin/coreclr,sagood/coreclr,ruben-ayrapetyan/coreclr,yeaicc/coreclr,AlexGhiondea/coreclr,neurospeech/coreclr,qiudesong/coreclr,SlavaRa/coreclr,swgillespie/coreclr,bartdesmet/coreclr,roncain/coreclr,pgavlin/coreclr,JosephTremoulet/coreclr,ramarag/coreclr,Dmitry-Me/coreclr,wateret/coreclr,mskvortsov/coreclr,martinwoodward/coreclr,AlexGhiondea/coreclr,naamunds/coreclr,mocsy/coreclr,neurospeech/coreclr,shahid-pk/coreclr,andschwa/coreclr,mskvortsov/coreclr,JonHanna/coreclr,kyulee1/coreclr,cydhaselton/coreclr,cydhaselton/coreclr,swgillespie/coreclr,josteink/coreclr,ramarag/coreclr,neurospeech/coreclr,dasMulli/coreclr,JonHanna/coreclr,yizhang82/coreclr,roncain/coreclr,russellhadley/coreclr,ruben-ayrapetyan/coreclr,mocsy/coreclr,yeaicc/coreclr,jhendrixMSFT/coreclr,benpye/coreclr,benpye/coreclr,poizan42/coreclr,wtgodbe/coreclr,manu-silicon/coreclr,alexperovich/coreclr,wkchoy74/coreclr,russellhadley/coreclr,andschwa/coreclr,sejongoh/coreclr,sjsinju/coreclr,swgillespie/coreclr,ramarag/coreclr,manu-silicon/coreclr,swgillespie/coreclr,sagood/coreclr,mocsy/coreclr,jamesqo/coreclr,benpye/coreclr,krytarowski/coreclr,yizhang82/coreclr,pgavlin/coreclr,Dmitry-Me/coreclr,shahid-pk/coreclr,kyulee1/coreclr,martinwoodward/coreclr,dasMulli/coreclr,ruben-ayrapetyan/coreclr,Dmitry-Me/coreclr,parjong/coreclr,mskvortsov/coreclr,bartonjs/coreclr,wateret/coreclr,shahid-pk/coreclr,AlexGhiondea/coreclr,krytarowski/coreclr,qiudesong/coreclr,naamunds/coreclr,martinwoodward/coreclr,JonHanna/coreclr,dasMulli/coreclr,Godin/coreclr,sperling/coreclr,mocsy/coreclr,cmckinsey/coreclr,sperling/coreclr,poizan42/coreclr,mokchhya/coreclr,mocsy/coreclr,cmckinsey/coreclr,schellap/coreclr,manu-silicon/coreclr,cmckinsey/coreclr,sperling/coreclr,jhendrixMSFT/coreclr,shahid-pk/coreclr,mmitche/coreclr,mmitche/coreclr,neurospeech/coreclr,pgavlin/coreclr,schellap/coreclr,krk/coreclr,yeaicc/coreclr,schellap/coreclr,cydhaselton/coreclr,benpye/coreclr,roncain/coreclr,wtgodbe/coreclr,wateret/coreclr,martinwoodward/coreclr,gkhanna79/coreclr,SlavaRa/coreclr,mskvortsov/coreclr,Dmitry-Me/coreclr,andschwa/coreclr,roncain/coreclr,AlexGhiondea/coreclr,YongseopKim/coreclr,poizan42/coreclr,jamesqo/coreclr,chuck-mitchell/coreclr,tijoytom/coreclr,cydhaselton/coreclr,krk/coreclr,yizhang82/coreclr,wkchoy74/coreclr,hseok-oh/coreclr,naamunds/coreclr,dpodder/coreclr,rartemev/coreclr,mmitche/coreclr