i#565 win8 syscall wrapper fix: KiFastSystemCall is not present on x64 ntdll
i#565 win8 syscall wrapper fix: KiFastSystemCall is not present on x64 ntdll

SVN-Revision: 1622

daksunt/dynamorio,AmesianX/dynamorio,bl4ckic3/dynamorio,code4bones/dynamorio,code4bones/dynamorio,daksunt/dynamorio,AmesianX/dynamorio,code4bones/dynamorio,code4bones/dynamorio,sigma-random/dynamorio,bl4ckic3/dynamorio,bl4ckic3/dynamorio,sigma-random/dynamorio,bl4ckic3/dynamorio,AmesianX/dynamorio,AmesianX/dynamorio,sigma-random/dynamorio,daksunt/dynamorio,AmesianX/dynamorio,bl4ckic3/dynamorio,daksunt/dynamorio,code4bones/dynamorio,daksunt/dynamorio,sigma-random/dynamorio,sigma-random/dynamorio