Merge remote-tracking branch 'remotes/nccl/master' into rccl_2.5.6

src/collectives/device/common_kernel.h

@@ -300,8 +300,6 @@ __device__ void ReduceCopyMulti(const int tid, const int nthreads,
   }
 }
 
-#define WARP_SIZE 64
-
 template<class FUNC, typename T, int UNROLL, int MINSRCS, int MAXSRCS, int MINDSTS, int MAXDSTS>
 __device__ void ReduceCopy128bMulti( const int w, const int nw, const int t,
     int nsrcs, const T* s[MAXSRCS], int ndsts, T* d[MAXDSTS],