This reverts commit dc3f758ddc9b76b1a1d3e63147521e56906fd7a4. Lit decided to show me the least interesting part of the test output, but from what I gather on Mac OS the DWARF stays in the object files (https://stackoverflow.com/a/12827463). So either split DWARF options do nothing or they produce files I don't know the name of that aren't .dwo, so I'm skipping these tests on Darwin.