[torch.package][easy] Add another opcode for matching pickle protocol 4+ correctly (#98674)
Summary: IL generates massive function names: which meant that the pickle opcode used is BINUNICODE instead of the short version -- and then it would silently get skipped while pickling with protocol 4.
Differential Revision: D44815351
Pull Request resolved: https://github.com/pytorch/pytorch/pull/98674
Approved by: https://github.com/ezyang
