We shouldn't require developers to build with --opt=on to run the unit tests, and sorter_test takes way way to long (more than 10 minutes?) if not built like that.

We need to find a way to make this test reasonably fast, either by intelligent use of mocks to not need to use such large sizes to trigger 'spilling', or by explicitly always compiling this one file with optimization enabled (either via scons, or some sort of #pragma optimize on like solution, if there is one for clang and gcc (doesn't look like clang has this yet)).

It is not reasonable to require developers to always pass --opt=on if they want a --dbg build.