refine reshape grad and double grad kernel, use tensor copy async (#29128) (#29446)

paddle/fluid/operators/reshape_op.cc

@@ -405,7 +405,9 @@ class ReshapeGradKernel {
     auto in_dims = d_x->dims();
 
     d_x->mutable_data(ctx.GetPlace(), d_out->type());
-    framework::TensorCopySync(*d_out, ctx.GetPlace(), d_x);
+    framework::TensorCopy(
+        *d_out, ctx.GetPlace(),
+        ctx.template device_context<platform::DeviceContext>(), d_x);
     d_x->Resize(in_dims);
   }
 };
@@ -419,7 +421,9 @@ class ReshapeDoubleGradKernel {
     auto out_dims = dd_out->dims();
 
     dd_out->mutable_data(ctx.GetPlace(), dd_x->type());
-    framework::TensorCopySync(*dd_x, ctx.GetPlace(), dd_out);
+    framework::TensorCopy(
+        *dd_x, ctx.GetPlace(),
+        ctx.template device_context<platform::DeviceContext>(), dd_out);
     dd_out->Resize(out_dims);
   }
 };