[ELF][PPC32] Fix canonical PLTs when the order does not match the PLT order Reviewed By: Bdragon28 Differential Revision: https://reviews.llvm.org/D75394 This is needed to fix miscompiled canonical PLTs on ppc32/lld10. Requested by: bdragon MFC after: 6 weeks X-MFC-With: 358851 Differential Revision: https://reviews.freebsd.org/D24109