tests/test-remotefilelog-strip.t

rust-matchers: fix quadratic complexity in `FileMatcher`

Concretely, this command:

```
$ echo hg up -r <nodeid>; time hg revert dir1 dir2 -r <othernode> --debug
hg up -r <nodeid>

real	0m14.690s
user	0m14.766s
sys	0m5.430s
```

was much slower despite using 16 cores before this change.
The approach taken here is the same one used in match.py, in exactmatcher.

This changeset was originally written by Valentin Gatien-Baron in a private
repository.
I have redacted the commit message and did a minor clean up of the code.

#require no-windows

  $ . "$TESTDIR/remotefilelog-library.sh"

  $ hg init master
  $ cd master
  $ cat >> .hg/hgrc <<EOF
  > [remotefilelog]
  > server=True
  > EOF
  $ echo x > x
  $ hg commit -qAm x

  $ cd ..

  $ hgcloneshallow ssh://user@dummy/master shallow -q
  1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
  $ cd shallow

  $ cat >> $TESTTMP/get_file_linknode.py <<EOF
  > from mercurial import node, registrar, scmutil
  > cmdtable = {}
  > command = registrar.command(cmdtable)
  > @command(b'debug-file-linknode', [(b'r', b'rev', b'.', b'rev')], b'hg debug-file-linknode FILE')
  > def debug_file_linknode(ui, repo, file, **opts):
  >   rflctx = scmutil.revsingle(repo.unfiltered(), opts['rev']).filectx(file)
  >   ui.status(b'%s\n' % node.hex(rflctx.ancestormap()[rflctx._filenode][2]))
  > EOF

  $ cat >> .hg/hgrc <<EOF
  > [ui]
  > interactive=1
  > [extensions]
  > strip=
  > get_file_linknode=$TESTTMP/get_file_linknode.py
  > [experimental]
  > evolution=createmarkers,allowunstable
  > EOF
  $ echo a > a
  $ hg commit -qAm msg1
  $ hg commit --amend 're:^$' -m msg2
  $ hg commit --amend 're:^$' -m msg3
  $ hg --hidden log -G -T '{rev} {node|short}'
  @  3 df91f74b871e
  |
  | x  2 70494d7ec5ef
  |/
  | x  1 1e423846dde0
  |/
  o  0 b292c1e3311f
  
  $ hg debug-file-linknode -r 70494d a
  df91f74b871e064c89afa1fe9e2f66afa2c125df
  $ hg --hidden strip -r 1 3
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/df91f74b871e-c94d67be-backup.hg

  $ hg --hidden log -G -T '{rev} {node|short}'
  o  1 70494d7ec5ef
  |
  @  0 b292c1e3311f
  
Demonstrate that the linknode points to a commit that is actually in the repo
after the strip operation. Otherwise remotefilelog has to search every commit in
the repository looking for a valid linkrev every time it's queried, such as
during push.
  $ hg debug-file-linknode -r 70494d a
  70494d7ec5ef6cd3cd6939a9fd2812f9956bf553