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 vararg1;

import tango.stdc.stdarg;

extern(C) int add(int n, ...)
{
    va_list ap=void;
    va_start(ap, n);
    int r;
    for (int i=0; i<n; i++)
        r += va_arg!(int)(ap);
    va_end(ap);
    return r;
}

void main()
{
    int i = add(4, 1,2,3,4);
    assert(i == 10);
}