fix build on PHP 8.6+

oauth.c

@@ -2913,7 +2913,7 @@ PHP_MINIT_FUNCTION(oauth)
 	zend_string_release(attribute_name_AllowDynamicProperties_class_OAuth);
 #endif
 	memcpy(&so_object_handlers, zend_get_std_object_handlers(), sizeof(zend_object_handlers));
-	so_object_handlers.offset = XtOffsetOf(php_so_object, zo);
+	so_object_handlers.offset = offsetof(php_so_object, zo);
 
 	so_object_handlers.read_property = oauth_read_member;
 	so_object_handlers.write_property = oauth_write_member;

php_oauth.h

@@ -259,7 +259,7 @@ typedef struct {
 } php_so_object;
 
 static inline php_so_object *so_object_from_obj(zend_object *obj) /* {{{ */ {
-    return (php_so_object*)((char*)(obj) - XtOffsetOf(php_so_object, zo));
+    return (php_so_object*)((char*)(obj) - offsetof(php_so_object, zo));
 }
 /* }}} */
 

provider.c

@@ -1238,7 +1238,7 @@ extern int oauth_provider_register_class(void) /* {{{ */
 #endif
 
 	memcpy(&oauth_provider_obj_hndlrs, zend_get_std_object_handlers(), sizeof(zend_object_handlers));
-	oauth_provider_obj_hndlrs.offset = XtOffsetOf(php_oauth_provider, zo);
+	oauth_provider_obj_hndlrs.offset = offsetof(php_oauth_provider, zo);
 	oauth_provider_obj_hndlrs.free_obj = oauth_provider_free_storage;
 
 	return SUCCESS;

provider.h

@@ -108,7 +108,7 @@ typedef struct {
 } php_oauth_provider;
 
 static inline php_oauth_provider *sop_object_from_obj(zend_object *obj) /* {{{ */ {
-    return (php_oauth_provider*)((char*)(obj) - XtOffsetOf(php_oauth_provider, zo));
+    return (php_oauth_provider*)((char*)(obj) - offsetof(php_oauth_provider, zo));
 }
 /* }}} */