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 vararg5;
import tango.core.Vararg;
extern(C) int printf(char*, ...);
void func(...)
{
    char[] str = va_arg!(char[])(_argptr);
    {printf("%.*s\n", str.length, str.ptr);}
}
void main()
{
    char[] str = "hello";
    func(str);
}