Update ZCSG(map_ptr_last) only if for_shm

Otherwise we may get a memory protection fault here. Updating of
ZCSG(map_ptr_last) is handled when loading from file cache to SHM.

ext/opcache/zend_persist.c

@@ -1089,7 +1089,9 @@ zend_persistent_script *zend_accel_script_persist(zend_persistent_script *script
 	} ZEND_HASH_FOREACH_END();
 	zend_persist_op_array_ex(&script->script.main_op_array, script);
 
-	ZCSG(map_ptr_last) = CG(map_ptr_last);
+	if (for_shm) {
+		ZCSG(map_ptr_last) = CG(map_ptr_last);
+	}
 
 	script->corrupted = 0;
 	ZCG(current_persistent_script) = NULL;