Walk into class body as well if it exists (normally undefined).

lib/ast.js

@@ -1070,6 +1070,9 @@ var AST_Class = DEFNODE("Class", "name extends properties", {
             if (this.extends) {
                 this.extends._walk(visitor);
             }
+            if (this.body) {
+                walk_body(this, visitor)
+            }
             this.properties.forEach(function(prop){
                 prop._walk(visitor);
             });