tests/test-check-jshint.t

py3: stringify IOError/OSError without loosing local character

Follows up fa4d333cac58. An environment error may contain non-ascii characters
on Windows, which should be encoded to a platform-native string.

#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