patch 8.0.0777: compiler warnings with 64 bit compiler

Problem:    Compiler warnings with 64 bit compiler.
Solution:   Add type casts. (Mike Williams)
diff --git a/src/version.c b/src/version.c
index 530663e..fe82a36 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    777,
+/**/
     776,
 /**/
     775,