[C++] Fix interaction between aka changes and DR1558 (PR92206)

[Richard Sandiford]

Jakub Jelinek <jakub@redhat.com> writes:
> On Wed, Nov 13, 2019 at 08:44:31AM +0000, Richard Sandiford wrote:
>> 	PR c++/92206
>> 	* g++.dg/cpp0x/alias-decl-pr92206-1.C: New test.
>> 	* g++.dg/cpp0x/alias-decl-pr92206-2.C: Likewise.
>> 	* g++.dg/cpp0x/alias-decl-pr92206-3.C: Likewise.
>
> This last test FAILs with -std=c++11:
> /usr/src/gcc/gcc/testsuite/g++.dg/cpp0x/alias-decl-pr92206-3.C:8:37: error: variable templates only available with '-std=c++14' or '-std=gnu++14'
>
> Fixed thusly, committed as obvious:
>
> 2019-11-14  Jakub Jelinek  <jakub@redhat.com>
>
> 	* g++.dg/cpp0x/alias-decl-pr92206-3.C: Require effective target c++14
> 	rather than c++11.

Thanks, and sorry for the breakage.  I obviously messed something up
during the testing.

Richard