#7110: have regrtest print test failures and tracebacks to stderr not stdout.

Patch by Sandro Tosi.
diff --git a/Lib/test/regrtest.py b/Lib/test/regrtest.py
index 366cedf..55c73e2 100755
--- a/Lib/test/regrtest.py
+++ b/Lib/test/regrtest.py
@@ -957,16 +957,16 @@
     except KeyboardInterrupt:
         raise
     except support.TestFailed as msg:
-        print("test", test, "failed --", msg)
-        sys.stdout.flush()
+        print("test", test, "failed --", msg, file=sys.stderr)
+        sys.stderr.flush()
         return FAILED, test_time
     except:
         type, value = sys.exc_info()[:2]
-        print("test", test, "crashed --", str(type) + ":", value)
-        sys.stdout.flush()
+        print("test", test, "crashed --", str(type) + ":", value, file=sys.stderr)
+        sys.stderr.flush()
         if verbose or debug:
-            traceback.print_exc(file=sys.stdout)
-            sys.stdout.flush()
+            traceback.print_exc(file=sys.stderr)
+            sys.stderr.flush()
         return FAILED, test_time
     else:
         if refleak: