port-vax/44155: GCC doesn't implement C++ exceptions for VAX

[uwe%NetBSD.org@localhost]

>Number:         44155
>Category:       port-vax
>Synopsis:       GCC doesn't implement C++ exceptions for VAX
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    port-vax-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Nov 26 22:20:00 +0000 2010
>Originator:     Valeriy E. Ushakov
>Release:        NetBSD 5.1
>Organization:
>Environment:
>Description:
GCC has some code for DWARF2 stack unwinding on VAX but it's neither correct, 
nor complete, so C++ exceptions currently don't work on VAX at all.

I've started investigating C++ exceptions in response to port-vax/43273 and I 
don't have any more time.  Besides, further work requires more knowledge of GCC 
internals that I posses, so I'm filing this to document my findings so far and 
leave it at that.

Margins of this web-form are too narrow, so all the details will be in a follow 
up mail to this PR.

>How-To-Repeat:

>Fix: