Add 0-byte test for send/recv (#865)

[ROCm/rccl commit: 0a01dc2f19]

projects/rccl/test/SendRecvTests.cpp

@@ -13,7 +13,7 @@ namespace RcclUnitTesting
 
     // Configuration
     std::vector<ncclDataType_t> const& dataTypes       = {ncclInt32, ncclFloat64};
-    std::vector<int>            const  numElements     = {1048576, 53327, 1024};
+    std::vector<int>            const  numElements     = {1048576, 53327, 1024, 0};
     bool                        const  inPlace         = false;
     bool                        const  useManagedMem   = false;