bundlerepo: implement safe phasecache
This patch makes bundlerepo use a subclass of phasecache that will allow phase
boundaries to be moved around, but will never write them to the underlying
repository.
<Include>
<?if $(var.Platform) = "x64" ?>
<?define IsX64 = yes ?>
<?else?>
<?define IsX64 = no ?>
<?endif?>
</Include>