Not sure why this was disabled in the first place (dates back to
<fbe9c04c5f>),
but it appears to be working for me.
This directory contains tests for the MIR file format parser and printer. It was necessary to split the tests across different targets as no single target covers all features available in machine IR. Tests for codegen passes should NOT be here but in test/CodeGen/sometarget. As a rule of thumb this directory should only contain tests using 'llc -run-pass none'.