Clear ServicesMap fields in the declared order

Constructors assign the fields in the same order.

Author: franferrax

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

@@ -834,11 +834,11 @@ Service getService(ServiceKey key) {
          * changes with the Properties map.
          */
         void clear() {
+            serviceSet.set(null);
             services.clear();
             legacySvcKeys.clear();
             serviceProps.clear();
             serviceAttrProps.clear();
-            serviceSet.set(null);
         }
 
         /*