patch 8.2.0872: XIM code is mixed with multi-byte code

Problem:    XIM code is mixed with multi-byte code.
Solution:   Move the XIM code to a separate file. (Yegappan Lakshmanan,
            closes #6177)
diff --git a/src/version.c b/src/version.c
index 7138ac5..ec8cda7 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    872,
+/**/
     871,
 /**/
     870,