extractpdfmark build failure on 10.6

[Werner LEMBERG]

>> something like this from another port earlier today should do, until
>> this issue finally gets fixed in the compiler run deps.
>> 
>> <https://github.com/macports/macports-ports/commit/c3b33c2df8abba42a855879b4097a17dee273fcc
>> <https://github.com/macports/macports-ports/commit/c3b33c2df8abba42a855879b4097a17dee273fcc>>
> 
> Small comment, but cctools works fine on all OSes versions, so there
> is really no need to put it inside a Darwin version check. In fact,
> for all OSes using Xcode 7 or older it provides a newer toolchain. I
> would just remove the Darwin version check..

I think the version check makes sense, since it is a reminder why the
code is there at all.  It is a gentle reminder that it should be
removed as soon the problem gets fixed at a higher level.

Apropos higher level & extractpdfmarks' Portfile: Shall I simply wait
until the c++11 portgroup file has been fixed?  I've already submitted

  https://github.com/macports/macports-ports/pull/2893

which would be unnecessary then.


    Werner