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 aa2;

void main()
{
    long[float] aa;
    long* p = 2.0f in aa;
    assert(!p);
    aa[4f] = 23;
    p = 4f in aa;
    assert(p);
    assert(*p == 23);
}