Invalidation must be done after inserting the new module

* Otherwise we could read the new Assumption but still miss the update which was done after.

Author: eregon

src/main/java/org/truffleruby/core/module/ModuleFields.java

@@ -295,10 +295,10 @@ public void include(RubyContext context, Node currentNode, RubyModule module) {
     private void performIncludes(ModuleChain inclusionPoint, Deque<RubyModule> moduleAncestors) {
         while (!moduleAncestors.isEmpty()) {
             RubyModule mod = moduleAncestors.pop();
+            inclusionPoint.insertAfter(mod);
             // Module#include only adds modules between the current class and the super class,
             // so invalidating the current class is enough as all affected lookups would go through the current class.
             newMethodsVersion(mod.fields.getMethodNames());
-            inclusionPoint.insertAfter(mod);
         }
     }
 
@@ -337,8 +337,8 @@ public void prepend(RubyContext context, Node currentNode, RubyModule module) {
             if (!(mod instanceof PrependMarker)) {
                 final RubyModule actualModule = mod.getActualModule();
                 if (!ModuleOperations.includesModule(rubyModule, actualModule)) {
-                    moduleFieldsToInvalidate.newMethodsVersion(actualModule.fields.getMethodNames());
                     cur.insertAfter(actualModule);
+                    moduleFieldsToInvalidate.newMethodsVersion(actualModule.fields.getMethodNames());
                     cur = cur.getParentModule();
                 }
             }