util: add a popoldest() method to lrucachedict
This allows consumers to prune the oldest item from the cache. This
could be useful for e.g. a consumer that wishes for the size of
items tracked by the cache to remain under a high water mark.
Differential Revision: https://phab.mercurial-scm.org/D4501
#require test-repo jshint hg10
$ . "$TESTDIR/helpers-testrepo.sh"
run jshint on all tracked files ending in .js except vendored dependencies
$ cd "`dirname "$TESTDIR"`"
$ testrepohg locate 'set:**.js' \
> 2>/dev/null \
> | xargs jshint