i#1796: disable warnings from suspected compiler bug
i#1796: disable warnings from suspected compiler bug

Adds -Wno-array-bounds to the compilation of unit_tests to avoid a bogus
compiler warning in gcc 5.1 in release build.

Fixes #1796

Review-URL: https://codereview.appspot.com/271800043

AmesianX/dynamorio,AmesianX/dynamorio,AmesianX/dynamorio,AmesianX/dynamorio,AmesianX/dynamorio