bug#9532: 24.0.50; `special-display-regexps' is no longer respected

[Drew Adams]

> Good news, for me at least: This bug seems to be fixed in 
> Emacs 24 pretest #1

Alas, no; I was mistaken.  The bug is still there, in both the first and second
deliveries of pretest #1.

I have non-nil pop-up-frames.
I have special-display-regexps set to: ("[ ]?[*][^*]+[*]").

And yet, when I do M-x report-emacs-bug, instead of buffer *unsent mail to
bug-gnu-emacs@gnu.org* being popped up in its own, special-display frame, that
buffer _replaces_ the current buffer in the same (non-special-display) frame.

IOW, `special-display-regexps' is still being ignored.

The reason I mistakenly thought that the bug had been fixed is that I do _not_
see the problem for *info* buffers: they are correctly opened in special-display
frames.

I don't know why there is this difference, since both buffers match
`special-display-regexps'.  Note that both `same-window-buffer-names' and
`same-window-regexps' are nil.

This bug has been dragging on for a very long time now.  It was fixed
temporarily with Martin's code, but things were broken again when his code was
dropped.

Please, pretty please fix this bug as a priority, before the next pretest.  Thx.