lit-test/compiler -> lit-test/test.

Other directories in lit-test will host various parts of
the test harness.

lit-test/test/lit.cfg

@@ -1,12 +1,13 @@
+import os, subprocess
 import lit.util
 import lit.formats
 
+root = os.path.join(os.path.dirname(__file__), '..')
+
 config.name = 'ARTIQ'
 config.test_format = lit.formats.ShTest()
 config.suffixes = ['.py']
-config.excludes = ['harness.py']
-config.test_source_root = os.path.dirname(__file__)
 
 python_executable = 'python3'
-harness = '{} {}'.format(python_executable, os.path.join(config.test_source_root, 'harness.py'))
+harness = '{} {}'.format(python_executable, os.path.join(root, 'harness.py'))
 config.substitutions.append( ('%python', harness) )