patch 9.0.1476: lines put in non-current window are not displayed

Problem:    Lines put in non-current window are not displayed. (Marius
            Gedminas)
Solution:   Don't increment the topline when inserting just above it.
            (closes #12212)

runtime/filetype.vim

@@ -273,6 +273,9 @@ if has("fname_case")
   autocmd BufRead,BufNewFile *.BUILD,BUILD		setf bzl
 endif
 
+" Busted (Lua unit testing framework - configuration files)
+au BufNewFile,BufRead .busted			setf lua
+
 " C or lpc
 au BufNewFile,BufRead *.c			call dist#ft#FTlpc()
 au BufNewFile,BufRead *.lpc,*.ulpc		setf lpc