patch 8.2.0877: cannot get the search statistics

Problem:    Cannot get the search statistics.
Solution:   Add the searchcount() function. (Fujiwara Takuya, closes #4446)

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    877,
 /**/
     876,
 /**/