build broken on Solaris

[Eric Botcazou]

> can you please try the attached? I'm sanity checking it on x86_64-linux
> multilib and if you can confirm it fixes the problem on Solaris I'll
> commit it to unbreak the bootstrap.

Thanks, Paolo.  Next error:

ld: fatal: libstdc++-symbols.ver-sun: 4632: symbol `typeinfo name for 
std::regex_error' is already defined in file: libstdc++-symbols.ver-sun

    ##_ZTSSt11regex_error (glob)
    _ZTSSt11regex_error;

    ##_ZTSSt[0-9][0-9][m-r]* (glob)
    _ZTSSt10money_base;
    _ZTSSt10moneypunctIcLb0EE;
    _ZTSSt10moneypunctIcLb1EE;
    _ZTSSt10moneypunctIwLb0EE;
    _ZTSSt10moneypunctIwLb1EE;
    _ZTSSt10ostrstream;
    _ZTSSt11range_error;
    _ZTSSt11regex_error;

-- 
Eric Botcazou