I noticed while editing Common Lisp code that emacs does not correctly
highlight the docstring of defstruct expressions, but highlights them
as if they were regular old strings.
This is a small patch against emacs CVS which rectifies the problem by
specifying the doc-string-elt property for defstruct. I'm using the
multi-tty branch, but I doubt this makes any difference here.
I'm not 100% sure that this is the correct place to make this
modification; I haven't fully explored how the different dialects of
Lisp are handled by lisp-mode; it appears to be primarily centered
around Elisp. But since Elisp defstruct is compatible with Common Lisp
defstruct (at least as far as the position of its docstring goes), I
don't see how this could actually break anything.