Update runtime files

runtime/autoload/dist/ft.vim

@@ -1,7 +1,7 @@
 " Vim functions for file type detection
 "
 " Maintainer:	Bram Moolenaar <Bram@vim.org>
-" Last Change:	2020 Jan 02
+" Last Change:	2020 Mar 30
 
 " These functions are moved here from runtime/filetype.vim to make startup
 " faster.
@@ -325,7 +325,7 @@ endfunc
 
 func dist#ft#FTmm()
   let n = 1
-  while n < 10
+  while n < 20
     let line = getline(n)
     if line =~ '^\s*\(#\s*\(include\|import\)\>\|@import\>\|/\*\)'
       setf objcpp