Fix av::copy in dialects to use capture-by-value

Change-Id: Ibce1488a1326f66b92b4d5b351230666b691ed31

samples/0_Intro/hcc_dialects/vadd_hip.cpp

@@ -27,22 +27,25 @@ int main(int argc, char *argv[])
     hipMalloc(&B_d, sizeBytes);
     hipMalloc(&C_d, sizeBytes);
 
-    // Initialize host data
+    // Initialize host memory
     for (int i=0; i<sizeElements; i++) {
         A_h[i] = 1.618f * i; 
         B_h[i] = 3.142f * i;
     }
 
+    // H2D Copy
     hipMemcpy(A_d, A_h, sizeBytes, hipMemcpyHostToDevice);
     hipMemcpy(B_d, B_h, sizeBytes, hipMemcpyHostToDevice);
 
-    // Launch kernel onto default accelerator:
+    // Launch kernel onto default accelerator
     int blockSize = 256;  // pick arbitrary block size
     int blocks = (sizeElements+blockSize-1)/blockSize; // round up to launch enough blocks
     hipLaunchKernel(vadd_hip, dim3(blocks), dim3(blockSize), 0, 0, A_d, B_d, C_d, sizeElements);
 
+    // D2H Copy
     hipMemcpy(C_h, C_d, sizeBytes, hipMemcpyDeviceToHost);
 
+    // Verify
     for (int i=0; i<sizeElements; i++) {
         float ref= 1.618f * i + 3.142f * i;
         if (C_h[i] != ref) {