debug mode maintenance patch

[Jonathan Wakely]

On 28/05/15 22:32 +0200, François Dumont wrote:
>Sorry, I saw it used so many times for macros that I though it was the 
>right way to report macro modifications.

The changelog style is fairly complicated :-)

>I also replicate Copyrights from debug.h to assertions.h.
>
>    * include/debug/debug.h (_GLIBCXX_DEBUG_ASSERT,
>    _GLIBCXX_DEBUG_PEDASSERT, _GLIBCXX_DEBUG_ONLY): Move definition...
>    * include/debug/assertions.h: ...here, new.
>    * include/debug/formatter.h
>    (struct _Error_formatter::_Is_iterator_value_type): New.
>    (struct _Error_formatter::_Is_instance): New.
>    (struct _Error_formatter::_Parameter): Make public and not friend
>    anymore.
>    (_Error_formatter::_Parameter::__instance): New _M_kind enum entry.
>    (_Error_formatter::_Parameter::__iterator_value_type): New _M_kind enum
>    entry.
>    (struct _Error_formatter::_Parameter::_Type): New.
>    (struct _Error_formatter::_Parameter::_Instance): New, inherit from
>    latter.
>    (union _Error_formatter::_Parameter::_M_variant): Reorganize.

I don't think we need to say 'struct' or 'union' either, because we're
not writing C, and they aren't needed in C++, but no big deal.

>Ok to commit ?

Yes, looks good, thanks.