Factor out the code to find gcc, and add a command-line option to override the default executable name. This should help cross-compilation by allowing a cross-gcc to be specified from the configuration file instead of only through the CC environment variable.

module classes10;

class C
{
    int i;
    override char[] toString()
    {
        return "foobar";
    }
}

void main()
{
    Object o = new C;
    char[] s = o.toString();
    assert(s == "foobar");
}