diffhelpers: fix variable declaration for MSVC (not C99)

mercurial/diffhelpers.c

@@ -21,15 +21,17 b' static void _fix_newline(PyObject *hunk,'
 	int hunksz = PyList_Size(hunk);
 	PyObject *s = PyList_GET_ITEM(hunk, hunksz-1);
 	char *l = PyString_AS_STRING(s);
+	int alen = PyList_Size(a);
+	int blen = PyList_Size(b);
+	char c = l[0];
+	PyObject *hline;
 	int sz = PyString_GET_SIZE(s);
+
 	if (sz > 1 && l[sz-2] == '\r')
 	        /* tolerate CRLF in last line */
 	        sz -= 1;
-	int alen = PyList_Size(a);
-	int blen = PyList_Size(b);
-	char c = l[0];
+	hline = PyString_FromStringAndSize(l, sz-1);
 
-	PyObject *hline = PyString_FromStringAndSize(l, sz-1);
 	if (c == ' ' || c == '+') {
 		PyObject *rline = PyString_FromStringAndSize(l+1, sz-2);
 		PyList_SetItem(b, blen-1, rline);