Tweak the test from 2721a2ca2e5e889d to work with PERL_UNICODE set.
Don't use a fixed iteration count in dist/threads-shared/t/stress.t

Looping 500,000 times takes between 0.025s and 1s depending on hardware and
optimisation levels on machines I have access to. For a fixed iteration
count, on a particularly slow machine the timeout can fire before all
threads have had a realistic chance to complete, but dropping the iteration
count will cause fast machines to finish each thread too quickly.

So use an initial busy loop (single-thread) to estimate a suitable iteration
count to use for the per-thread test loop.
Update File-Fetch to CPAN version 0.38

  [DELTA]

  Changes for 0.38        Thu Jan 10 20:52:53 2013
  =================================================
  * Add support for an optional tempdir_root
    parameter (Kent Fredric)
expand comment in Perl_pad_tidy

make it clear that /$var/ is only eval-able in the presence of
'use re eval'; then generally tidy and reformat the comment.
Make perlbug recommend perlcommunity.pod over Usenet

Suggested by Dave Mitchell.
pod/perlcommunity.pod: mention blogs.perl.org and Stack Overflow

And mention that use.perl.org is now read-only.
embed.fnc: Fix flags for _invlist_dump

This debugging function is normally #ifdef'd out, but should it e
enabled, the flags were wrong.
lib/warnings/regcomp: Add note about better place for these

reg_mesg.t has some more infrastructure, so it is probably easier
to add new tests there.
regexp.t: Add a period in test name skip reason

This is easier to read.