message: cpplint: Downgrade 'runtime/references' warnings to advice
  Summary: Reason: this conflicts with Poplar's API.
  Reviewers: #tensorflow, georgep, hakons
diff: "include": [
  "(^tensorflow/compiler/plugin/poplar/.*\\.(c|cpp|C|cc|c\\+\\+|cxx|h|hpp)$)",
  "(^tensorflow/python/ipu/.*\\.(c|cpp|C|cc|c\\+\\+|cxx|h|hpp)$)"
  - ]
  + ],
  + "severity": {
  + "runtime/references": "advice"
  + }
  },
  "yapf": {
  "type": "yapf",
  