[Bug libstdc++/53579] libstdc++ configure use CXXFLAGS instead of CXXFLAGS_FOR_TARGET

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53579

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=43538

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Oh wait config/mt-gnu has changed to:
mt-gnu:CXXFLAGS_FOR_TARGET += -D_GNU_SOURCE