I guess it is not the intention of the standard, but it is possible. High integrity does not mean never fail, only that the failure rate is low enough that additional protection is not required.
It is possible to re-arrange the risk evaluation to extract a required probability of failure for the part in question. You can then consider if it is plausible to claim the part can meet that specification.
In fact, there are many high integrity parts, but it is clear the intention of the standard is to consider situations where there would normally be additional protection and the manufacturer would like to go against normal practice and rely on a single part.
It could be for example that the severity of harm is moderate, and there may be factors external to the device which help to reduce the overall probability of harm (for example, with a diagnostic device, the diagnosis might be made based on several sources of information, not just the device in question). So a failure rate of 0.001 for the part in question might be enough for "high integrity". In that case, a software library could be OK for high integrity, and probably nobody expects it to be even written up as high integrity.
However, for an infant incubator, where failure of control is severe (death) and there are few external factors, a high integrity component might need to be in the order of a 0.0000001 failure rate over the life of the device. At those kind of probabilities, it is not only the library but the memory it is stored in. It would be a stretch to consider any part as high integrity for that situation. If a manufacturer did, they would need some solid documentation and objective evidence, and there is no question about it being written up as a high integrity component.