Port GC fix to CoreRT runtime
Port GC fix to CoreRT runtime

This corresponds to the following CoreCLR fix:

https://github.com/dotnet/coreclr/commit/bfe57c6f88442b4c4b4bc0754443ce61035d24c8

[tfs-changeset: 1564255]

shrah/corert,tijoytom/corert,krytarowski/corert,manu-silicon/corert,mjp41/corert,schellap/corert,kyulee1/corert,kyulee1/corert,tijoytom/corert,gregkalapos/corert,shrah/corert,sandreenko/corert,manu-silicon/corert,mjp41/corert,kyulee1/corert,mjp41/corert,botaberg/corert,tijoytom/corert,shrah/corert,krytarowski/corert,gregkalapos/corert,yizhang82/corert,sandreenko/corert,krytarowski/corert,shrah/corert,schellap/corert,yizhang82/corert,yizhang82/corert,manu-silicon/corert,botaberg/corert,gregkalapos/corert,schellap/corert,yizhang82/corert,botaberg/corert,schellap/corert,krytarowski/corert,botaberg/corert,tijoytom/corert,gregkalapos/corert,kyulee1/corert,manu-silicon/corert,sandreenko/corert,mjp41/corert,mjp41/corert,sandreenko/corert,schellap/corert,manu-silicon/corert