patch 7.4.1708

Problem:    New regexp engine does not work properly with EBCDIC.
Solution:   Define equivalence class characters. (Owen Leibman)

src/version.c

@@ -748,6 +748,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1708,
 /**/
     1707,
 /**/