message: Allow creating nullptr AttrHeaderBase to support TypedAttrBase::dyn_cast. TypedAttrBase::dyn_cast should return a nullptr if type mismatch.
diff: @@ -2206,6 +2206,7 @@ cuda_py_test(
  size = "medium",
  srcs = ["linalg_ops_test.py"],
  tags = ["no_windows_gpu"],
  + tfrt_enabled = True,
  deps = [
  "//tensorflow/python:array_ops",
  "//tensorflow/python:client_testlib",
  