copy: move _forwardcopies file logic to a function
Moves the _forwardcopies missingfiles logic to a separate function so that other
extensions which need to prefetch information about the files being
processed have a hook point.
This saves extensions from having to recompute this information themselves, and
thus saves several seconds off of various commands (like rebase).
copy: move mergecopies file logic to a function
Moves the mergecopies nonoverlap logic to a separate function so that other
extensions which may need to prefetch information about the files being
processed have a hook point.
This saves extensions from having to recompute this information themselves, and
thus saves several seconds off of various commands (like rebase).