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Kavon Farvardin
b7d57f3bcd
Ordinary base protocols use fixed-indexing to access the base index. That means adding another base protocol to an existing protocol can break the order of the entries, and thus clients, because we otherwise order the base entires with TypeDecl::compare. Reparentable protocols are meant to be resilient to that, so we order them at the end of the base entries list, just before the other resilient entries in the witness table. This patch completes the picture, by having the reparentable protocol entries be indexed resiliently, in the same manner as associated conformances. The difference is that we can skip the call to `swift_getAssociatedConformanceWitness` and compute the index directly by finding the distance of the descriptors, because we know all base protocol witness table entries are eagarly instantiated. Using this distance protects us from the ordering problems of entries among all of the reparentable base protocols. resolves rdar://173409851