swift

8b8ed52f - If a member is a witness to any @objc requirement, don't call it a near miss.

If a member is a witness to any @objc requirement, don't call it a near miss. When @objc inference was extended to look at the conformances of superclasses, the code that diagnosed near misses was not similarly updated, so we could end up producing a near-miss diagnostic on a declaration that was already a witness to another protocol. Use the same witness-finding logic that we use for @objc inference so this doesn't happen again. Fixes the rest of rdar://problem/27348369 (cherry picked from commit 5267c6a269e7caf6baf1f6cb313c01c00da5e010)