tests/test-debugrename.t

merge: move an inspection of the dirstate from record to calculate phase

The intent is clearly to have `calculateupdates()` figure out what
actions need to be taken and `recordupdates()` to make necessary
modifications to the dirstate. However, in the
`ACTION_PATH_CONFLICT_RESOLVE` case, there was one little inspection
of copy information done in `recordupdates()`. This patch moves that
to `calculateupdates()`. That will help with the next patch, which
makes `merge.update()` work better with `overlayworkingctx` (copies
should be recorded there too, even though we skip the
`recordupdates()` step).

Differential Revision: https://phab.mercurial-scm.org/D8615

  $ hg init
  $ echo a > a
  $ hg ci -Am t
  adding a

  $ hg mv a b
  $ hg ci -Am t1
  $ hg debugrename b
  b renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3

  $ hg mv b a
  $ hg ci -Am t2
  $ hg debugrename a
  a renamed from b:37d9b5d994eab34eda9c16b195ace52c7b129980

  $ hg debugrename --rev 1 b
  b renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3