Add ZEND_STR_CLONE known string

Author: TimWolla

Zend/zend_string.h

@@ -575,6 +575,7 @@ EMPTY_SWITCH_DEFAULT_CASE()
 	_(ZEND_STR_UNKNOWN,                "unknown") \
 	_(ZEND_STR_UNKNOWN_CAPITALIZED,    "Unknown") \
 	_(ZEND_STR_EXIT,                   "exit") \
+	_(ZEND_STR_CLONE,                  "clone") \
 	_(ZEND_STR_EVAL,                   "eval") \
 	_(ZEND_STR_INCLUDE,                "include") \
 	_(ZEND_STR_REQUIRE,                "require") \

build/gen_stub.php

@@ -3057,6 +3057,7 @@ class PropertyInfo extends VariableLike
         "parent" => "ZEND_STR_PARENT",
         "username" => "ZEND_STR_USERNAME",
         "password" => "ZEND_STR_PASSWORD",
+        "clone" => "ZEND_STR_CLONE",
     ];
 
     /**