pkg/45716: emacs (various versions) dies on unwind stuff in gcc 4.5

[David Holland <dholland-pbugs%netbsd.org@localhost>]

(manual forward to the mailing list b/c I screwed up)

>Number:         45716
>Category:       pkg
>Synopsis:       emacs (various versions) dies on unwind stuff in gcc 4.5
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Dec 16 14:55:00 +0000 2011
>Originator:     David A. Holland
>Release:        NetBSD current
>Organization:
>Environment:
n/a
>Description:

When built with gcc 4.5, multiple versions of emacs die during build
(temacs receives SIGSEGV) due to something bogus going on in unwind
handling.

Christos committed a workaround to NetBSD HEAD in October so this
problem is not live, but it ought to be investigated to figure out if
emacs or gcc or NetBSD or what is at fault.

I'm not clear at the moment on whether this is an amd64-specific issue
or not.

>How-To-Repeat:

Revert Christos's workaround (Christos should please forward the
necessary info to this PR) and build emacs. emacs20 is smallest and we
believe it's affected; but this hasn't actually been confirmed yet.

>Fix: