patch 9.0.0510: Chatito files are not recognized

Problem:    Chatito files are not recognized.
Solution:   Add a pattern for Chatito files. (closes #11174)

runtime/filetype.vim

@@ -299,6 +299,9 @@ au BufNewFile,BufRead cfengine.conf		setf cfengine
 " ChaiScript
 au BufRead,BufNewFile *.chai			setf chaiscript
 
+" Chatito
+au BufNewFile,BufRead *.chatito			setf chatito
+
 " Comshare Dimension Definition Language
 au BufNewFile,BufRead *.cdl			setf cdl
 

src/testdir/test_filetype.vim

@@ -108,6 +108,7 @@ let s:filename_checks = {
     \ 'ch': ['file.chf'],
     \ 'chaiscript': ['file.chai'],
     \ 'chaskell': ['file.chs'],
+    \ 'chatito': ['file.chatito'],
     \ 'chill': ['file..ch'],
     \ 'chordpro': ['file.chopro', 'file.crd', 'file.cho', 'file.crdpro', 'file.chordpro'],
     \ 'cl': ['file.eni'],

src/version.c

@@ -699,6 +699,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    510,
 /**/
     509,
 /**/