patch 8.1.2375: no suffucient testing for registers

Problem:    No suffucient testing for registers.
Solution:   Add more test cases. (Yegappan Lakshmanan, closes #5296)
            Fix that "p" on last virtual column of tab inserts spaces.

src/version.c

@@ -742,6 +742,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2375,
 /**/
     2374,
 /**/