Fix crash importing from a directory special remote that contains a broken
symlink.
The crash was in listImportableContentsM but some other places in
Remote.Directory also seemed like they could have the same problem.
Also audited for other places that have such a problem. Not all calls
to getFileStatus are bad, in some cases it's better to crash on something
unexpected. For example, `git-annex import path` when the path is a broken
symlink should crash, the same as when it does not exist. Many of the
getFileStatus calls are like that, particularly when they involve
.git/annex/objects which should never have a broken symlink in it.
Fixed a few other possible cases of the problem.
Sponsored-by: Lawrence Brogan on Patreon
Trick the linker into not doing unncessary work searching for optimised
libraries that are not present, by symlinking the directories where
optimised libs would be to the main lib dir.
This reduces the ENOENT of git-annex init by about 1/2. The linker always
finds the files where it looks first time now. I have not looked at what
the wall clock speedup might be, it's probably rather small.
If a x86-64-v5 comes to be, the list will need to be extended. And there
may be other directories used on some machines that I have missed. Not done
for arm64 yet, or any uncommon architectures.
Sponsored-by: Dartmouth College's Datalad project
