Use __attribute__((assume())) in ZEND_ASSUME when available

Author: iluuu1994

Zend/zend_portability.h

@@ -89,6 +89,9 @@
 
 #if defined(ZEND_WIN32) && !defined(__clang__)
 # define ZEND_ASSUME(c)	__assume(c)
+#elif defined(__GNUC__) && !defined(__clang__) && __GNUC__ >= 13
+/* GCC emits a warning when __attribute__ appears directly after a label, so prefix with ;. */
+# define ZEND_ASSUME(c)	;__attribute__((assume(c)))
 #elif defined(__clang__) && __has_builtin(__builtin_assume)
 # pragma clang diagnostic ignored "-Wassume"
 # define ZEND_ASSUME(c)	__builtin_assume(c)