Fix 'ValueError: low is out of bounds for int32' error in test_int64
Fix 'ValueError: low is out of bounds for int32' error in test_int64

The type can be specified directly to randint; casting it after the
fact won't work after the min/max values given are in the i64 range.

onnx/onnx,onnx/onnx,onnx/onnx,onnx/onnx