Log Message:
Update p5-Digest-MD5 to 2.20

   More synchronization with tweaks Jarkko have done to the
   bleadperl test suite. This time various EBCDIC hacks.

   Outside PERL_CORE the md5-aaa.t test loaded the wrong version of
   the module (and would fail if no previous Digest::MD5 was installed).

   One more test suite update from Jarkko to sync it
   even better with bleadperl.

   Changes #12954 and #16173 from bleadperl.  Documentation typo fix
   and some signed/unsigned mismatches that Microsoft's C compiler
   complained about.

   The EBCDIC-aware md5-aaa.t from bleadperl.