Swift 5 migration: Fix switch warnings

We now get a warning when switching over enums from system
frameworks even when we handle all public cases because
there can be future cases that aren't handled.

When such a future case is introduced, we'll get a warning.

WireGuard/Shared/Model/Endpoint.swift

@@ -36,6 +36,8 @@ extension Endpoint {
             return "\(address):\(port)"
         case .ipv6(let address):
             return "[\(address)]:\(port)"
+        @unknown default:
+            fatalError()
         }
     }
 
@@ -78,6 +80,8 @@ extension Endpoint {
             return true
         case .ipv6:
             return true
+        @unknown default:
+            fatalError()
         }
     }
 
@@ -89,6 +93,8 @@ extension Endpoint {
             return nil
         case .ipv6:
             return nil
+        @unknown default:
+            fatalError()
         }
     }
 }

WireGuard/WireGuard/Tunnel/TunnelStatus.swift

@@ -27,6 +27,8 @@ import NetworkExtension
             self = .reasserting
         case .invalid:
             self = .inactive
+        @unknown default:
+            fatalError()
         }
     }
 }
@@ -54,6 +56,8 @@ extension NEVPNStatus: CustomDebugStringConvertible {
         case .disconnecting: return "disconnecting"
         case .reasserting: return "reasserting"
         case .invalid: return "invalid"
+        @unknown default:
+            fatalError()
         }
     }
 }

WireGuard/WireGuardNetworkExtension/DNSResolver.swift

@@ -117,6 +117,8 @@ extension Endpoint {
             hostname = "\(address)"
         case .ipv6(let address):
             hostname = "\(address)"
+        @unknown default:
+            fatalError()
         }
 
         var resultPointer = UnsafeMutablePointer<addrinfo>(OpaquePointer(bitPattern: 0))