RS lib: fix conditional compilation to work with clang.
RS lib: fix conditional compilation to work with clang.

chanwit/qfs,fengshao0907/qfs,fengshao0907/qfs,qnu/qfs,thebigbrain/qfs,chanwit/qfs,chanwit/qfs,qnu/qfs,quantcast/qfs,fengshao0907/qfs,qnu/qfs,thebigbrain/qfs,quantcast/qfs,quantcast/qfs,quantcast/qfs,thebigbrain/qfs,quantcast/qfs,thebigbrain/qfs,quantcast/qfs,thebigbrain/qfs,thebigbrain/qfs,fengshao0907/qfs,qnu/qfs,qnu/qfs,chanwit/qfs,fengshao0907/qfs,chanwit/qfs,thebigbrain/qfs,qnu/qfs,qnu/qfs,chanwit/qfs,quantcast/qfs,fengshao0907/qfs,fengshao0907/qfs,thebigbrain/qfs,chanwit/qfs,quantcast/qfs,qnu/qfs,chanwit/qfs,fengshao0907/qfs