tests/test-debugrename.t

rust: fix non-utf8 char in requirements.rs

Apparently Phabricator detect `rust/hg-core/src/requirements.rs` file as non
utf8 ‽, and mark it as binary.  During application it ended up being non-utf8
and this made Rust (and as a result heptapod) very angry::

    error: couldn't read hg-core/src/requirements.rs: stream did not contain valid UTF-8
      --> hg-core/src/lib.rs:11:9
       |
    11 | pub mod requirements;
       |         ^^^^^^^^^^^^

    error: aborting due to previous error

    error: could not compile `hg-core`.

The after "fixing", the file content has no character matching the following
regexp:

  [^0-9-a-zA-Z /(|).,{}!\[\]:"&=>?_*-;<`'#]

So we should be fine, unless Phabricator does something funny again.

Differential Revision: https://phab.mercurial-scm.org/D9444

  $ 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