message: Remove GlobalKernelRegistry (returning void*) from the op kernel API.
  This was used with RegisterKernels which was removed now.
diff: @@ -1304,8 +1304,6 @@ class Name : public KernelDefBuilder {
  return new __VA_ARGS__(context); \
  });
  -void* GlobalKernelRegistry();
  -
  // If node_def has a corresponding kernel registered on device_type,
  // returns OK and fill in the kernel def and kernel_class_name. <def> and
  // <kernel_class_name> may be null.
  