[Bug libstdc++/64103] conflicting definitions in parallel/algo.h and algorithmfwd.h

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64103

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |5.0

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
And additionally r217069

Those fixes would be safe to backport.