bug#21581: 25.0.50; doc string of `load'

[Eli Zaretskii]

> Date: Mon, 28 Sep 2015 10:22:51 -0700 (PDT)
> From: Drew Adams <drew.adams@oracle.com>
> 
> Say that FILE is a string.

  load is a built-in function in ‘C source code’.

  (load FILE &optional NOERROR NOMESSAGE NOSUFFIX MUST-SUFFIX)

  Execute a file of Lisp code named FILE.

Do you really mean we need to say explicitly that a file's name is a
string in Emacs?  What else can it be?  From the ELisp manual:

  24.8 File Names
  ===============

  Files are generally referred to by their names, in Emacs as elsewhere.
  File names in Emacs are represented as strings.  The functions that
  operate on a file all expect a file name argument.

I think this is so basic that we can always say "a file's name" and
assume the reader must know it can only be a string.