SingleList: Fix compilation.

Signed-off-by: Michael Lippautz <michael.lippautz@gmail.com>
FCQueue: Add FlatCombining Queue to framework.

Source:
D. Hendler, I. Incze, N. Shavit, and M. Tzafrir. Flat combining and the
synchronization-parallelism tradeoff. In Proceedings of the 22nd ACM symposium
on Parallelism in algorithms and architectures, SPAA ’10, pages 355–364, New
York, NY, USA, 2010. ACM.

Signed-off-by: Michael Lippautz <michael.lippautz@gmail.com>
FCQueue: Enable in producer/consumer benchmark.

Signed-off-by: Michael Lippautz <michael.lippautz@gmail.com>