Set contains_keywords flag for implicit gets($/, chomp: true) method …

…call to handle -l CLI option

src/prism.c

@@ -21905,6 +21905,7 @@ wrap_statements(pm_parser_t *parser, pm_statements_node_t *statements) {
             ));
 
             pm_arguments_node_arguments_append(arguments, (pm_node_t *) keywords);
+            pm_node_flag_set((pm_node_t *) arguments, PM_ARGUMENTS_NODE_FLAGS_CONTAINS_KEYWORDS);
         }
 
         pm_statements_node_t *wrapped_statements = pm_statements_node_create(parser);