Log Message:
Update to 20190516. From the changelog:

Benchmarking:
- Speed tests now call cpucycles() before setting resource limits. This
  is important on platforms where cpucycles() needs to read files.

Verification:
- Support for SignExt and several more peephole optimizations, working
  towards support for simpler symbolic-execution backend. Various
  updates to work with angr8 and python3.