ONNX LinearClassifier short classlabels abort PoC

• control-linearclassifier-valid-classlabels.onnx
• malicious-linearclassifier-short-classlabels.onnx
• build_poc.py
• repro.py

• control-linearclassifier-valid-classlabels.onnx
  • checker passes
  • shape inference passes
  • InferenceSession(...) succeeds
  • sess.run(...) succeeds
• malicious-linearclassifier-short-classlabels.onnx
  • checker passes
  • shape inference passes
  • InferenceSession(...) succeeds
  • sess.run(...) aborts