Ensure resolution occurs once; fix SR-6391.

This commit ensures that the `resolve` functionality only calculates
addresses and names once, as appears to be originally intended.
Furthermore, this mitigates a bug where addresses would be endlessly
appended to the `addresses` array, causing long term unbounded heap
growth.

Author: swizzlr

Foundation/Host.swift

@@ -95,6 +95,7 @@ open class Host: NSObject {
             }
             ifa = ifaValue.ifa_next
         }
+        _resolved = true
 #endif
     }