Port fix for potential GC hole in ConditionalWeakTable (#3459)
Port fix for potential GC hole in ConditionalWeakTable (#3459)

https://github.com/dotnet/coreclr/pull/11307
tijoytom/corert,tijoytom/corert,gregkalapos/corert,yizhang82/corert,yizhang82/corert,shrah/corert,gregkalapos/corert,krytarowski/corert,shrah/corert,tijoytom/corert,yizhang82/corert,gregkalapos/corert,yizhang82/corert,shrah/corert,tijoytom/corert,krytarowski/corert,shrah/corert,botaberg/corert,krytarowski/corert,botaberg/corert,krytarowski/corert,botaberg/corert,botaberg/corert,gregkalapos/corert