Fix py2.6--use Popen instead of check_output

llvm/tests/__init__.py

@@ -45,9 +45,15 @@ def run(verbosity=1):
 
         for test in isolated_tests:
             print(('testing %s' % test).center(80))
-            term = subprocess.check_output([sys.executable, '-m', test],
+
+        cmd = [sys.executable, '-m', test]
+        p = subprocess.Popen(cmd, stdout=subprocess.PIPE,
                              stderr=subprocess.STDOUT)
-            print(term)
+        for line in p.stdout:
+            print(line, end='')
+        p.wait()
+        if p.returncode:
+            raise Exception("%s returned: %d" % p.returncode)
 
     return testresult