tests/test-hgk.t

dirstate.walk: don't keep track of normalized files in parallel

Rev 2bb13f2b778c changed the semantics of the work list to store (normalized,
non-normalized) pairs. All the tuple creation and destruction hurts perf: on a
large repo on OS X, 'hg status' went from 3.62 seconds to 3.78.

It also is unnecessary in most cases:
- it is clearly unnecessary on case-sensitive filesystems.
- it is also unnecessary when filenames have been read off of disk rather than
  being supplied by the user.

The only case where the non-normalized case is required at all is when the file
is unknown.

To eliminate most of the perf cost, keep trace of whether the directory needs
to be normalized at all with a boolean called 'alreadynormed'. Pay the cost of
directory normalization only when necessary.

For the above large repo, 'hg status' goes to 3.63 seconds.

Minimal hgk check

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "hgk=" >> $HGRCPATH
  $ hg init repo
  $ cd repo
  $ echo a > a
  $ hg ci -Am adda
  adding a
  $ hg debug-cat-file commit 0
  tree a0c8bcbbb45c
  parent 000000000000
  author test 0 0
  revision 0
  branch default
  phase draft
  
  adda
  $ echo b > b
  $ hg ci -Am addb
  adding b
  $ hg log -T '{node}\n'
  102a90ea7b4a3361e4082ed620918c261189a36a
  07f4944404050f47db2e5c5071e0e84e7a27bba9

  $ hg debug-diff-tree 07f494440405 102a90ea7b4a
  :000000 100664 000000000000 1e88685f5dde N	b	b
  $ hg debug-diff-tree 07f494440405 102a90ea7b4a --patch
  diff --git a/b b/b
  new file mode 100644
  --- /dev/null
  +++ b/b
  @@ -0,0 +1,1 @@
  +b

Ensure that diff-tree output isn't affected by diffopts
  $ hg --config diff.noprefix=True debug-diff-tree 07f494440405 102a90ea7b4a
  :000000 100664 000000000000 1e88685f5dde N	b	b
  $ hg --config diff.noprefix=True debug-diff-tree --patch 07f494440405 102a90ea7b4a
  diff --git a/b b/b
  new file mode 100644
  --- /dev/null
  +++ b/b
  @@ -0,0 +1,1 @@
  +b

  $ cd ..