[PATCH] Fix -Wsystem-header warnings in libstdc++

[Jonathan Wakely]

On 04/12/17 23:07 +0000, Jonathan Wakely wrote:
>On 01/12/17 16:10 +0000, Jonathan Wakely wrote:
>>On 01/12/17 15:11 +0000, Jonathan Wakely wrote:
>>>This fixes a number of warnings that show up with -Wsystem-headers
>>
>>This fixes some more.
>
>And some more, this time for -Wunused, -Wcomment, and
>-Wvariadic-macros.
>
>Tested powerpc64le-linux, committed to trunk.
>
>The purpose of these is not only to reduce noise if users use
>-Wsystem-headers, but to get us to a place where PR 50871 can be fixed
>(i.e. build and test libstdc++ without having useful warnings
>suppressed by the #pragma GCC system_header lines).

This warning remains:

/home/jwakely/gcc/8/include/c++/8.0.0/bits/valarray_array.h:56:12: warning: type qualifiers ignored on function return type [-Wignored-qualifiers]
     inline _Tp*__restrict__
            ^~~

I think we can just remove the __restrict__.