tests/test-mq-qsave.t

wrapfunction: use sysstr instead of bytes as argument in "perf"

This is as valid and simpler, it will help us to eventually get ride of
`safehasattr`.

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH

  $ hg init repo
  $ cd repo

  $ echo 'base' > base
  $ hg ci -Ambase
  adding base

  $ hg qnew -mmqbase mqbase

  $ hg qsave
  $ hg qrestore 2
  restoring status: hg patches saved state