run-test: keep track of the "real hg" binary before we replace it with a proxy...
run-test: keep track of the "real hg" binary before we replace it with a proxy
When using `--rhg` or `--chg`, the `_hgcommand` attribute get replaced because
we actually install them. This make it hard to refer to the installed hg in
_installhg. So we keep track of it in a new attribute that we will use in the
next few patches.