Fix Windows build (re r77461)
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index b7874f1..e74165a 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -5791,10 +5791,10 @@
         goto nothing;
 
     if (str1->length == str2->length) {
+        Py_ssize_t i;
         /* same length */
         if (str1->length == 0)
             goto nothing;
-        Py_ssize_t i;
         if (str1->length == 1) {
             /* replace characters */
             Py_UNICODE u1, u2;