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 memory1;

extern(C) int printf(char*,...);

void main()
{
    auto a = new int[16];
    {printf("array.length = %u\n", a.length);}
    {a.length = a.length + 1;}
    {printf("array.length = %u\n", a.length);}
    {assert(a.length == 17);}
}