with-wrapper-hook is obsolete; how to replace it?

[Paul Eggert <eggert@cs.ucla.edu>]

When I run ‘make compile-always’ from the lisp subdirectory I see diagnostics
like this:

In buffer-substring--filter:
simple.el:4058:52:Warning: ‘with-wrapper-hook’ is an obsolete macro (as of
    24.4); use a <foo>-function variable modified by ‘add-function’.

How do I alter the code to use add-function instead? It's not immediately
obvious. That is, if there is source code like this:

    (with-wrapper-hook filter-buffer-substring-functions (beg end delete) BODY)

where filter-buffer-substring-functions is defined like this:

  (defvar filter-buffer-substring-functions nil
    "This variable is a wrapper hook around `buffer-substring--filter'.")

then what should I replace the source code with?