patch 8.0.1786: no test for 'termwinkey'

Problem:    No test for 'termwinkey'.
Solution:   Add a test.  Make feedkeys() handle terminal_loop() returning
            before characters are consumed.
diff --git a/src/version.c b/src/version.c
index 01bd9a1..52b5436 100644
--- a/src/version.c
+++ b/src/version.c
@@ -762,6 +762,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1786,
+/**/
     1785,
 /**/
     1784,