Add AtleastNOperands trait and update tf-ops test

* TensorFlow Control Flow supports variadic number of control inputs, add variant of NOperands to support at least N operands;
* Update example:
  - All ops will produce control output;
  - Use tf$name for mapping back to TensorFlow (a op can have a name as well as an attribute _name, using tf$name disambiguates that);

PiperOrigin-RevId: 206621280
1 file changed
tree: b06fb3a54ae40b446f84a243c8d74507a7ba7e58
  1. include/
  2. lib/
  3. test/
  4. tools/
  5. utils/
  6. .clang-format
  7. LICENSE.TXT