gather_nd::Prepare reads `indices_nd` from `indices->dims->data[
indices_rank - 1]`, which is an attacker-controlled int32 value coming
from the .tflite model's `indices` tensor shape. The existing bound
check only validated the upper bound:

  if (indices_nd > params_rank) { error }

A *negative* value passes this check (negative is not > positive) and
propagates into the rest of Prepare:

  // output_rank wraps to a huge positive int because subtracting a
  // negative is the same as adding a positive
  const int output_rank = indices_rank + params_rank - indices_nd - 1;
  TfLiteIntArray* output_shape = TfLiteIntArrayCreate(output_rank);
  ...
  for (int i = indices_nd; i < params_rank; ++i) {
    output_shape->data[output_index++] = params->dims->data[i];   // OOB read
  }

Two distinct memory-safety primitives result:

1. The loop iterates `for (int i = indices_nd; i < params_rank; ++i)`
   with i starting at a negative int32 and ending at a small positive
   value. Each iteration reads `params->dims->data[i]` for negative
   i — an OOB read of params->dims->data on the order of ~2^31 entries.

2. `output_index` runs past `output_rank` and writes into
   `output_shape->data[]` past the just-allocated TfLiteIntArray
   storage, corrupting heap memory adjacent to the allocation.

3. The wrapped `output_rank` also produces a garbage TfLiteIntArray
   shape, which `ResizeTensor` then uses to size the output tensor;
   the kernel Eval path later walks `reference_ops::GatherNd` with the
   un-wrapped intended sizes, producing a heap-buffer-overflow write
   whose length and content are controlled by the model.

A malicious .tflite that contains a GatherNd op whose `indices` tensor
has its innermost dimension set to a negative int32 (e.g. via a crafted
flatbuffer) is enough to trigger the chain.

Fix
---

Validate `indices_nd >= 0` in addition to the existing
`indices_nd > params_rank` check, and add a defensive
`TF_LITE_ENSURE(context, output_rank >= 0)` after the subtraction so
any future regression that introduces a wrap is caught before the
TfLiteIntArrayCreate / loop combination.

Also drop <stdint.h> in favor of <cstdint> per the style review on
PR tensorflow#115031.

This is the same family of fix as PRs tensorflow#115031 / tensorflow#115452 / tensorflow#115453 /
tensorflow#115454 / tensorflow#115455 / tensorflow#115456 / tensorflow#115457 / tensorflow#115458, with the addition
that gather_nd carries a *second* OOB primitive (the loop reading
params->dims->data[negative]).