This reverts commit 7a34bd7c28.
Broke windows build. Can apparently fix with /Zc:preprocessor flag
for windows but need a Windows dev to make that fix.
And make them part of the blender_test runner. The one exception is blenlib
performance tests, which we don't want to run by default. They remain in their
own executable.
Differential Revision: https://developer.blender.org/D8498