[committed] libstdc++: Fix std::atomic<std::shared_ptr<T>> for AIX [PR104101]

[Hans-Peter Nilsson]

> From: Jonathan Wakely via Gcc-patches <gcc-patches@gcc.gnu.org>
> Date: Wed, 19 Jan 2022 02:03:58 +0100

> Tested powerpc64le-linux, powerpc-aix, pushed to trunk.
> 
> 
> This fixes a testsuite failure

I'm guessing the actual number is in the tens.

> on AIX.

...and by the looks of it, some 60 regressions (as counted
by contrib/regression/btest-gcc.sh) on newlib targets too
for the same reason.

brgds, H-P