Add definition _TARGET_64BIT_ in clrdefinitions.cmake
Add definition _TARGET_64BIT_ in clrdefinitions.cmake

ruben-ayrapetyan/coreclr,wtgodbe/coreclr,krk/coreclr,mmitche/coreclr,wtgodbe/coreclr,poizan42/coreclr,mmitche/coreclr,cshung/coreclr,poizan42/coreclr,wtgodbe/coreclr,mmitche/coreclr,krk/coreclr,wtgodbe/coreclr,poizan42/coreclr,cshung/coreclr,mmitche/coreclr,ruben-ayrapetyan/coreclr,ruben-ayrapetyan/coreclr,poizan42/coreclr,cshung/coreclr,krk/coreclr,ruben-ayrapetyan/coreclr,mmitche/coreclr,poizan42/coreclr,wtgodbe/coreclr,mmitche/coreclr,wtgodbe/coreclr,ruben-ayrapetyan/coreclr,krk/coreclr,krk/coreclr,cshung/coreclr,poizan42/coreclr,cshung/coreclr,ruben-ayrapetyan/coreclr,cshung/coreclr,krk/coreclr