Fix uouv in array_column

column_long and index_long might not be set, but are still used as arguments.
They are not actually used if column_str is set, but it's better to initialize
them anyway, if only to make MemorySanitizer happy.

Author: iluuu1994

ext/standard/array.c

@@ -4513,10 +4513,10 @@ PHP_FUNCTION(array_column)
 	HashTable *input;
 	zval *colval, *data, rv;
 	zend_string *column_str = NULL;
-	zend_long column_long;
+	zend_long column_long = 0;
 	bool column_is_null = 0;
 	zend_string *index_str = NULL;
-	zend_long index_long;
+	zend_long index_long = 0;
 	bool index_is_null = 1;
 
 	ZEND_PARSE_PARAMETERS_START(2, 3)