Merge branch 'tb/midx-bitmap-corruption-fix'

A bug that made multi-pack bitmap and the object order out-of-sync, making the .midx data corrupt, has been fixed. * tb/midx-bitmap-corruption-fix: pack-bitmap.c: gracefully fallback after opening pack/MIDX midx: read `RIDX` chunk when present t/lib-bitmap.sh: parameterize tests over reverse index source t5326: move tests to t/lib-bitmap.sh t5326: extract `test_rev_exists` t5326: drop unnecessary setup pack-revindex.c: instrument loading on-disk reverse index midx.c: make changing the preferred pack safe t5326: demonstrate bitmap corruption after permutation