patch 8.0.1634: the ex_vimgrep() function is too long

Problem:    The ex_vimgrep() function is too long.
Solution:   Split it in smaller functions. (Yegappan Lakshmanan)
diff --git a/src/version.c b/src/version.c
index 4ae79e7..ca668c1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -767,6 +767,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1634,
+/**/
     1633,
 /**/
     1632,