bug#43579: g++ does not provide std::fegetround

[Andreas Enge]

On Wed, Sep 23, 2020 at 06:21:21PM +0200, Andreas Enge wrote:
> Now it would be interesting to have a look at config.log for gcc...

I did so with gcc-10.2.0 and executed ./configure in the subdirectory
libstdc++-v3. The relevant part of config.log is this:
configure:16462: checking for ISO C99 support to TR1 in <fenv.h>
configure:16490: g++ -c  -std=c++98  conftest.cpp >&5
configure:16490: $? = 0
configure:16497: result: yes

This is when trying to compile gcc-10.2.0 with gcc-10.2.0; so somehow
our bootstrapping process does something differently when creating the
final user facing gcc.

Andreas