swift

219073be - Revert "[region-isolation] Make "unknown pattern error" always an error."

Revert "[region-isolation] Make "unknown pattern error" always an error." This reverts commit b63781f7ba7796a8ad20b79c56f1ad961eac6286. We found some cases where due to malformed IR that we allow through due to either us compiling for strict-concurrency=complete+swift-5 or swift-6 + preconcurrency, that we can actually have actor isolation mismatch. I am going to in a subsequent commit add a better phrasing here. But for now, just undo the conversion from error -> warning. rdar://131757602