amend: enable support for using the secret phase
This comes from the evolve extension's version of amend. The logic was already
in place, and appears to be the last of the trivial things that can be enabled.
Differential Revision: https://phab.mercurial-scm.org/D6856
amend: enable support for closing the branch
This comes from the evolve extension's version of amend. The logic was already
in place.
Differential Revision: https://phab.mercurial-scm.org/D6855