message: Remove certain symbols from tensorflow.__all__.
  When deleting `compiler`, `core` and `python` symbols from `tensorflow`,
  we currently don't remove them from `__all__`. This breaks anybody who
  tries to do `from tensorflow import *`.
diff: @@ -118,7 +118,11 @@ if _running_from_pip_package():
  # pylint: disable=undefined-variable
  try:
  del python
  + if '__all__' in vars():
  + vars()['__all__'].remove('python')
  del core
  + if '__all__' in vars():
  + vars()['__all__'].remove('core')
  except NameError:
  # Don't fail if these modules are not available.
  # For e.g. this file will be originally placed under tensorflow/_api/v1 which
  @@ -129,6 +133,8 @@ except NameError:
  # others don't exist.
  try:
  del compiler
  + if '__all__' in vars():
  + vars()['__all__'].remove('compiler')
  except NameError:
  pass
  # pylint: enable=undefined-variable
  