build broken on Solaris

[Eric Botcazou]

> Next try ;)

Next next error .-)

ld: fatal: libstdc++-symbols.ver-sun: 4635: symbol `vtable for 
std::regex_error' is already defined in file: libstdc++-symbols.ver-sun

    ##_ZTVSt11regex_error (glob)
    _ZTVSt11regex_error;

    ##_ZTVSt[0-9][0-9][m-r]* (glob)
    _ZTVSt10moneypunctIcLb0EE;
    _ZTVSt10moneypunctIcLb1EE;
    _ZTVSt10moneypunctIwLb0EE;
    _ZTVSt10moneypunctIwLb1EE;
    _ZTVSt10ostrstream;
    _ZTVSt11range_error;
    _ZTVSt11regex_error;

-- 
Eric Botcazou