Log Message:
Updated afl to 2.11b.

--------------
Version 2.11b:
--------------

  - Fixed a minor typo in instrumented_cmp, spotted by Hanno Eissfeldt.

  - Added a missing size check for deterministic insertion steps.

  - Made an improvement to afl-gotcpu when -Z not used.

  - Fixed a typo in post_library_png.so.c in experimental/. Spotted by Kostya
    Serebryany.