contrib/wix/defines.wxi

formatter: unblock storing fctx as a template resource

To keep templateformatter._renderitem() simple, a repo instance is looked
through ctx if available. This is probably good for future subrepo support
where ctx.repo() may be different from the global repo.

<Include>

  <?if $(var.Platform) = "x64" ?>
    <?define IsX64 = yes ?>
  <?else?>
    <?define IsX64 = no ?>
  <?endif?>

</Include>