[PATCH] libstdc++: implement locale support for AIX

[Rainer Orth]

Hi Clement,

> Here is a better version of the patch. 
> All tests are on Linux are passing. Few have been disabled as 
> they are working only with GNU model. 
> For AIX, few failures remains. I haven't XFAIL them yet, as I 
> want to know if they AIX only or related to the model itself. 
>
> A few part still need to be improved (dg-require-localmodel,
> std::locale:global, FreeBSD specific #ifdef). 
> But at least it can be tested in most of the platforms as is. 
>
> Note that I'll stop working on it until gcc12. Mostly because gcc
> is on freeze but also because I've more urgent stuff to do right now. 
> Of course any feedbacks is welcome ! But I might not send a
> new patch if it requires too much time (at least not right now). 
>
> Thanks anyway Rainer and Jonathan for your help ! I hope this 
> version suits you better !

very much so, thanks a lot for your work!  I've just looked over it to
determine what changes to config/os/solaris are necessary and found a
few nits:

* There are minor formatting issues:

  Should the linebreak in the extern inline definitions of strtof_l be
  after the return type, not before, matching GNU coding standards?  It
  may well be that the C++ style is different, though.

  Unrelated whitespace changes in xpg7/ctype_members.cc

* The changes in the copyright ranges need to be undone, given that this
  is just a renamed/augmented version of the previous dragonfly code.

* Seeing the __DragonFly__ || __FreeBSD__ again, I had a quick look at
  the FreeBSD 12.2 headers and found that localeconv_l does take a
  locale_t arg, just like uselocale.  DragonFlyBSD seems to be the same
  according to their online manuals.  I expect to give the code a try in
  a FreeBSD 12.2 VM at some point to check.

* While you now define _GLIBCXX_C_LOCALE_XPG7 in
  config/locale/xpg7/c_locale.h, config/os/aix/ctype_configure_char.cc
  still tests the previous _GLIBCXX_C_LOCALE_IEEE_2008.

Nothing tested yet, just wanted to point those out ASAP.

	Rainer

-- 
-----------------------------------------------------------------------------
Rainer Orth, Center for Biotechnology, Bielefeld University