patch 8.1.2127: the indent.c file is a bit big

Problem:    The indent.c file is a bit big.
Solution:   Move C-indent code a a new cindent.c file.  Move other
            indent-related code to indent.c. (Yegappan Lakshmanan,
            closes #5031)

src/version.c

@@ -753,6 +753,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2127,
 /**/
     2126,
 /**/