sidedata: test we can successfully write sidedata
For now we just write them and rejoice on the lack of crashes.
Differential Revision: https://phab.mercurial-scm.org/D6896
fixbundle() {
grep -v 'saving bundle' | grep -v 'saved backup' | \
grep -v added | grep -v adding | \
grep -v "unable to find 'e' for patching" | \
grep -v "e: No such file or directory" | \
cat
}