Restore the fix for SwiftASTContext::IsPossibleDynamicType in a more minimalistic fashion. NFC compared to the older patch I just reverted
Restore the fix for SwiftASTContext::IsPossibleDynamicType in a more minimalistic fashion. NFC compared to the older patch I just reverted

apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb