o Major bugfixes (compilation, rust):
    - Rust tests can now build and run successfully with the
      --enable-fragile-hardening option enabled.
      Doing this currently requires the rust beta channel; it will
      be possible with stable rust as of rust version 1.31 is out.
      Patch from Alex Crichton.
      Fixes bugs 27272, 27273, and 27274.
      Bugfix on 0.3.1.1-alpha.