copy & rename can ignore removed source files
As mercurial now distinguishes deleted files from removed files,
we can skip removed source files while copying or renaming.
1:3aa14bbc23d90:8633637036c13aa14bbc23d9 tip8633637036c18633637036c1+8633637036c13aa14bbc23d9 tipmerging file13aa14bbc23d9 tip3aa14bbc23d9 tip3aa14bbc23d9 tip3aa14bbc23d9 tip