The rename detection logic sorts a list of rename source candidates
by similarity to pick the best candidate, which means that a tie
between sources with the same similarity is broken by the original
location in the original candidate list (which is sorted by path).
Force the sorting by similarity done with a stable sort, which is
not promised by system supplied qsort(3), to ensure consistent
results across platforms.
* js/diff-rename-force-stable-sort:
diffcore_rename(): use a stable sort
Move git_sort(), a stable sort, into into libgit.a
772cad0afb