patch 8.2.5110: icon filetype not recognized from the first line

Problem:    Icon filetype not recognized from the first line.
Solution:   Add a check for the first line. (Doug Kearns)
diff --git a/runtime/autoload/dist/script.vim b/runtime/autoload/dist/script.vim
index b926f31..86070a0 100644
--- a/runtime/autoload/dist/script.vim
+++ b/runtime/autoload/dist/script.vim
@@ -189,6 +189,10 @@
   elseif name =~ 'gforth\>'
     set ft=forth
 
+    # Icon
+  elseif name =~ 'icon\>'
+    set ft=icon
+
   endif
 enddef