contrib/editmergeps.bat

commit: factor out empty commit check to `basectx.isempty()`

This enables reuse in other places, e.g. those dealing with `memctx`.

Differential Revision: https://phab.mercurial-scm.org/D8729

@echo off
powershell -NoProfile -ExecutionPolicy unrestricted -Command "& '%~dp0\editmergeps.ps1' %*"