Issue #16714: use 'raise' exceptions, don't 'throw'.

Patch by Serhiy Storchaka.
diff --git a/Lib/traceback.py b/Lib/traceback.py
index 8cb9e28..da17d3a 100644
--- a/Lib/traceback.py
+++ b/Lib/traceback.py
@@ -166,7 +166,7 @@
     # >>> raise string1, string2  # deprecated
     #
     # Clear these out first because issubtype(string1, SyntaxError)
-    # would throw another exception and mask the original problem.
+    # would raise another exception and mask the original problem.
     if (isinstance(etype, BaseException) or
         isinstance(etype, types.InstanceType) or
         etype is None or type(etype) is str):