tests/test-merge-subrepos.t

largefiles: don't mangle filesets when fixing up the log matcher

The fileset-generated.t test previously failed with this:

  +  hg: parse error: unknown identifier: .hglf/modified
  +  (did you mean 'modified'?)
  +  [255]

Filesets will find the standins on their own, without any help.  While that's
useful for some things like modified(), clean(), etc., it is wrong for things
like size().  Proper fileset support for largefiles is not trivial, but this was
failing with just the extension enabled on a normal repo.

  $ hg init

  $ echo a > a
  $ hg ci -qAm 'add a'

  $ hg init subrepo
  $ echo 'subrepo = http://example.net/libfoo' > .hgsub
  $ hg ci -qAm 'added subrepo'

  $ hg up -qC 0
  $ echo ax > a
  $ hg ci -m 'changed a'
  created new head

  $ hg up -qC 1
  $ cd subrepo
  $ echo b > b
  $ hg add b
  $ cd ..

Should fail, since there are added files to subrepo:

  $ hg merge
  abort: uncommitted changes in subrepository 'subrepo'
  [255]