c_api: TF_NewTensor now allows pinned managed objects to be passed down to TF (needed different deallocator arg type)

src/TensorFlowNET.Core/APIs/c_api.cs

@@ -53,7 +53,13 @@ namespace Tensorflow
             return handle == IntPtr.Zero ? String.Empty : Marshal.PtrToStringAnsi(handle);
         }
 
-        public delegate void Deallocator(IntPtr data, IntPtr size, ref bool deallocator);
+        public delegate void Deallocator(IntPtr data, IntPtr size, ref DeallocatorArgs args);
+
+        public struct DeallocatorArgs
+        {
+            public bool deallocator_called;
+            public IntPtr gc_handle;
+        }
 
         [DllImport(TensorFlowLibName)]
         public static unsafe extern IntPtr TF_Version();

src/TensorFlowNET.Core/Tensors/c_api.tensor.cs

@@ -71,7 +71,7 @@ namespace Tensorflow
         /// <param name="deallocator_arg"></param>
         /// <returns></returns>
         [DllImport(TensorFlowLibName)]
-        public static extern IntPtr TF_NewTensor(TF_DataType dataType, long[] dims, int num_dims, IntPtr data, UIntPtr len, Deallocator deallocator, ref bool deallocator_arg);
+        public static extern IntPtr TF_NewTensor(TF_DataType dataType, long[] dims, int num_dims, IntPtr data, UIntPtr len, Deallocator deallocator, ref DeallocatorArgs deallocator_arg);
 
         /// <summary>
         /// Return the number of dimensions that the tensor has.