message: [TF] Provide header-only variants of ndarray_tensor and pybind11_status.
  Also modify numpy_lib to not have direct deps on tensorflow:{lib,framework}.  They're
  never used and make it impossible for numpy_lib to be used in external pybindings.
diff: @@ -396,8 +396,6 @@ cc_library(
  srcs = ["lib/core/numpy.cc"],
  hdrs = ["lib/core/numpy.h"],
  deps = [
  - "//tensorflow/core:framework",
  - "//tensorflow/core:lib",
  "//third_party/py/numpy:headers",
  "//third_party/python_runtime:headers",
  ],
  @@ -503,23 +501,41 @@ cc_library(
  )
  cc_library(
  - name = "pybind11_status",
  + name = "pybind11_status_headers",
  hdrs = [
  "lib/core/py_exception_registry.h",
  "lib/core/pybind11_status.h",
  "//tensorflow/c:headers",
  + "//tensorflow/c/eager:headers",
  + ],
  + features = [
  + "-parse_headers",
  ],
  - features = ["-parse_headers"],
  visibility = tf_external_workspace_visible(visibility),
  deps = [
  "//tensorflow/c:tf_status_headers",
  - "//tensorflow/core:lib",
  + "//tensorflow/core:core_cpu_headers_lib",
  "//tensorflow/core:protos_all_cc",
  "//third_party/python_runtime:headers",
  "@pybind11",
  ],
  )
  +cc_library(
  + name = "pybind11_status",
  + hdrs = [
  + "lib/core/py_exception_registry.h",
  + "lib/core/pybind11_status.h",
  + "//tensorflow/c:headers",
  + ],
  + features = ["-parse_headers"],
  + visibility = tf_external_workspace_visible(visibility),
  + deps = [
  + ":pybind11_status_headers",
  + "//tensorflow/core:lib",
  + ],
  +)
  +
  cc_library(
  name = "pybind11_proto",
  hdrs = ["lib/core/pybind11_proto.h"],
  @@ -822,6 +838,34 @@ cc_library(
  ],
  )
  +cc_library(
  + name = "ndarray_tensor_headers",
  + hdrs = [
  + "lib/core/bfloat16.h",
  + "lib/core/ndarray_tensor.h",
  + "lib/core/ndarray_tensor_bridge.h",
  + "lib/core/numpy.h",
  + "lib/core/safe_ptr.h",
  + "//tensorflow/c:headers",
  + "//tensorflow/c:pywrap_required_hdrs",
  + "//tensorflow/c/eager:headers",
  + ],
  + features = [
  + "-parse_headers",
  + ],
  + visibility = tf_external_workspace_visible(visibility + [
  + "//learning/deepmind/courier:__subpackages__",
  + ]),
  + deps = [
  + ":numpy_lib",
  + "//tensorflow/c:tf_status_headers",
  + "//tensorflow/core:core_cpu_headers_lib",
  + "//tensorflow/core:framework_internal_headers_lib",
  + "//third_party/py/numpy:headers",
  + "//third_party/python_runtime:headers",
  + ],
  +)
  +
  cc_library(
  name = "ndarray_tensor",
  srcs = ["lib/core/ndarray_tensor.cc"],
  