patch 9.0.1415: Crystal files are not recognized

Problem:    Crystal files are not recognized.
Solution:   Add a pattern for Crystal files. (Amaan Qureshi, closes #12175)

runtime/filetype.vim

@@ -439,6 +439,9 @@ au BufNewFile,BufRead *.cook			setf cook
 " needs to be inspected.
 au BufNewFile,BufRead *.cql			setf cqlang
 
+" Crystal
+au BufNewFile,BufRead *.cr			setf crystal
+
 " CSV Files
 au BufNewFile,BufRead *.csv			setf csv
 

src/testdir/test_filetype.vim

@@ -131,6 +131,7 @@ let s:filename_checks = {
     \ 'cqlang': ['file.cql'],
     \ 'crm': ['file.crm'],
     \ 'crontab': ['crontab', 'crontab.file', '/etc/cron.d/file', 'any/etc/cron.d/file'],
+    \ 'crystal': ['file.cr'],
     \ 'cs': ['file.cs', 'file.csx'],
     \ 'csc': ['file.csc'],
     \ 'csdl': ['file.csdl'],

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1415,
 /**/
     1414,
 /**/