8250246: Address reliance on default constructors in security libs

Reviewed-by: mullan

src/java.base/share/classes/java/security/KeyFactorySpi.java

@@ -69,6 +69,11 @@ import java.security.spec.InvalidKeySpecException;
 
 public abstract class KeyFactorySpi {
 
+    /**
+     * Constructor for subclasses to call.
+     */
+    public KeyFactorySpi() {}
+
     /**
      * Generates a public key object from the provided key
      * specification (key material).