[Static Runtime] Fix prim::If tuple corner case (#85446)
Summary: We currently assume that a tuple output implies that the prim::If node returns multiple unpacked outputs, but this is not guaranteed to be the case. Add some logic to return the wrapped tuple if necessary
Test Plan: New unit test
Differential Revision: D39712050
Pull Request resolved: https://github.com/pytorch/pytorch/pull/85446
Approved by: https://github.com/tenpercent
