preserve parameter attributes during C++ decl smashing

[David Mandelin]

Jason Merrill wrote:
> David Mandelin wrote:
>> I'm not sure if it's OK to share the DECL_ATTRIBUTES(...) properties 
>> like that, so please check that out specifically in reviewing the patch. 
>
> That should be fine, since one of the decls is going to be garbage 
> anyway.
Good. Thanks.
> This needs a ChangeLog entry, like Taras included with the earlier 
> patch.  Also, have you completed a copyright assignment?
>
The same one Taras used before is fine:

gcc/cp/ChangeLog:

2009-04-22  David Mandelin <dmandelin@mozilla.com>:
       * decl.c (duplicate_decls): Preserve parameter attributes

We have a copyright assignment that covers all our work as Mozilla 
employees, including this work.

--
Dave