Revert "Revert adoption of CUDA indexing in general - this can only work with later versions of the compiler, just like module based dispatch, and thus must be guarded against usage in earlier (e.g. 1.6) versions."

This reverts commit d2fd1f5

hipamd/tests/src/runtimeApi/device/hipDeviceSynchronize.cpp

@@ -34,7 +34,7 @@ THE SOFTWARE.
 #define NUM_STREAMS 2
 
 __global__ void Iter(hipLaunchParm lp, int *Ad, int num){
-    int tx = threadIdx.x + blockIdx.x * blockDim.x;
+    int tx = hipThreadIdx_x + hipBlockIdx_x * hipBlockDim_x;
     // Kernel loop designed to execute very slowly... ... ...   so we can test timing-related behavior below
     if(tx == 0){
         for(int i = 0; i<num;i++){