Add American Fuzzy Lop (afl) to third_party/afl/

third_party/afl/src/experimental/README.experiments

+Here's a quick overview of the stuff you can find in this directory:
+
+  - argv_fuzzing         - a simple wrapper to allow cmdline to be fuzzed
+                           (e.g., to test setuid programs).
+
+  - asan_cgroups         - a contributed script to simplify fuzzing ASAN
+                           binaries with robust memory limits on Linux.
+
+  - bash_shellshock      - a simple hack used to find a bunch of
+                           post-Shellshock bugs in bash.
+
+  - canvas_harness       - a test harness used to find browser bugs with a 
+                           corpus generated using simple image parsing 
+                           binaries & afl-fuzz.
+
+  - clang_asm_normalize  - a script that makes it easy to instrument
+                           hand-written assembly, provided that you have clang.
+
+  - crash_triage         - a very rudimentary example of how to annotate crashes
+                           with additional gdb metadata.
+
+  - distributed_fuzzing  - a sample script for synchronizing fuzzer instances
+                           across multiple machines (see parallel_fuzzing.txt).
+
+  - instrumented_cmp     - an experiment showing how a custom memcmp() or
+                           strcmp() can be used to work around one of the
+                           limitations of afl-fuzz.
+
+  - libpng_no_checksum   - a sample patch for removing CRC checks in libpng.
+
+  - persistent_demo      - an example of how to use the LLVM persistent process
+                           mode to speed up certain fuzzing jobs.
+
+  - post_library         - an example of how to build postprocessors for AFL.
+
+Note that the minimize_corpus.sh tool has graduated from the experimental/
+directory and is now available as ../afl-cmin. The LLVM mode has likewise
+graduated to ../llvm_mode/*.
+
+Most of the tools in this directory are meant chiefly as examples that need to
+be tweaked for your specific needs. They come with some basic documentation,
+but are not necessarily production-grade.