It would tell you that the system is inconsistent
EDIT: I'm working under the hypothetical situation in which PA could prove its consistency. I know it can't but assuming that it could prove it's own consistency you still couldn't conclude that it was consistent since an inconsistent system can prove it's consistency.
The point being, having PA prove its own consistency couldn’t tell you anything of value even in the case that Godel’s theorems were not true. This is an interesting phenomenon. The only way to know a system is consistent is to know all of its theorems.