tests/histedit-helpers.sh

match: add tests for visitdir functionality

There are a few cases that we could have done better with some additional logic;
I tried to annotate these when I noticed them, but may have missed some. The
tests are not exhaustive; there are certainly some patterns that I didn't test
well, and many that I didn't test at all.

The primary motivation was to get coverage on visitdir so that I can cover
identical cases in a similar method I'm working on, to make sure that this new
method behaves the same (or better).

Differential Revision: https://phab.mercurial-scm.org/D4128

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
}