Propagate VALID UTF8 flag when interning string via Opcache

Author: Girgias

ext/opcache/ZendAccelerator.c

@@ -549,7 +549,7 @@ zend_string* ZEND_FASTCALL accel_new_interned_string(zend_string *str)
 	STRTAB_COLLISION(s) = *hash_slot;
 	*hash_slot = STRTAB_STR_TO_POS(&ZCSG(interned_strings), s);
 	GC_SET_REFCOUNT(s, 2);
-	GC_TYPE_INFO(s) = GC_STRING | ((IS_STR_INTERNED | IS_STR_PERMANENT) << GC_FLAGS_SHIFT);
+	GC_TYPE_INFO(s) = GC_STRING | ((IS_STR_INTERNED | IS_STR_PERMANENT) << GC_FLAGS_SHIFT)| (ZSTR_IS_VALID_UTF8(str) ? IS_STR_VALID_UTF8 : 0);
 	ZSTR_H(s) = h;
 	ZSTR_LEN(s) = ZSTR_LEN(str);
 	memcpy(ZSTR_VAL(s), ZSTR_VAL(str), ZSTR_LEN(s) + 1);