patch 9.0.1425: "wat" and "wast" files are one filetype

Problem:    "wat" and "wast" files are one filetype.
Solution:   Add a separate filetype for "wat" files. (Amaan Qureshi,
            closes #12165)
diff --git a/src/version.c b/src/version.c
index 2438733..63428d3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1425,
+/**/
     1424,
 /**/
     1423,