tests/blacklists/README

largefiles: handle that a found standin file doesn't exist when removing it

I somehow ended up in a situation where hg crashed on an unlink I introduced in
328545c7d8a1.

I don't know how it happened and can't reproduce it. It seems like it only can
happen when the file is removed between the time of check in a working
directory context walk that finds a standin file, and the time of use when we
try to remove it because the corresponding largefile doesn't exist.

But better safe than sorry: replace the plain unlink with unlinkpath with
ignoremissing=True. That will also remove remaining empty directories, which
arguably is more correct.

Put here definitions of blacklists for run-tests.py

Create a file per blacklist. Each file should list the names of tests that you
want to be skipped.
File names are meant to be used as targets for run-tests.py --blacklist
option.
Lines starting with # are ignored. White spaces are stripped.

e.g. if you create a blacklist/example file containing:
 test-hgrc
 # some comment
 test-help
then calling "run-tests.py --blacklist blacklists/example" will exclude
test-hgrc and test-help from the list of tests to run.