patch 9.0.2079: Not all Dart files detected

Problem:  Not all Dart files detected
Solution: Add shebang filetype detection for Dart

closes: #13449

Signed-off-by: Doug Kearns <dougkearns@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/autoload/dist/script.vim

@@ -221,6 +221,10 @@ export def Exe2filetype(name: string, line1: string): string
   elseif name =~ '^janet\>'
     return 'janet'
 
+    # Dart
+  elseif name =~ '^dart\>'
+    return 'dart'
+
   endif
 
   return ''

src/testdir/test_filetype.vim

@@ -955,7 +955,8 @@ def s:GetScriptChecks(): dict<list<list<string>>>
     crystal: [['#!/path/crystal']],
     rexx:   [['#!/path/rexx'],
             ['#!/path/regina']],
-    janet: [['#!/path/janet']],
+    janet:  [['#!/path/janet']],
+    dart:   [['#!/path/dart']],
   }
 enddef
 

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2079,
 /**/
     2078,
 /**/