Fixed ModuleInfo generation to no longer use the ModuleInfo class' default initializer for types/defaults, it's unsafe as initializers don't necesarily match the "formal" type. There might be explicit padding. Changed -g switch to emit DW_LANG_D debug info, make demangling work with a patched GDB, still more work to do for full support of D's Dwarf extensions. Added getNullValue helper method.

module typeinfo3;

typedef int int_t;

void main()
{
    /*int_t i;
    auto ti = typeid(typeof(i));
    printf("%s\n",ti.toString.ptr);
    assert(ti.toString() == "typeinfo3.int_t");
    assert(ti.next !is null);
    assert(ti.next.toString() == "int");
    assert(ti.init is null);*/
}