run-tests: add support for RTUNICODEPEDANTRY environment variable

based on 73e4a02e6d23

tests/run-tests.py

@@ -69,6 +69,13 b' except ImportError:'
 from xml.dom import minidom
 import unittest
 
+if os.environ.get('RTUNICODEPEDANTRY', False):
+    try:
+        reload(sys)
+        sys.setdefaultencoding("undefined")
+    except NameError:
+        pass
+
 osenvironb = getattr(os, 'environb', os.environ)
 processlock = threading.Lock()