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 mini.delegate2;

void main()
{
    int foo = 42;
    int bar()
    {
        return foo;
    }
    int delegate() dg = &bar;
    assert(dg() == foo);
}