bpo-39114: Fix tracing of except handlers with name binding (GH-17769)

bpo-39114: Fix tracing of except handlers with name binding (GH-17769)

When producing the bytecode of exception handlers with name binding (like `except Exception as e`) we need to produce a try-finally block to make sure that the name is deleted after the handler is executed to prevent cycles in the stack frame objects. The bytecode associated with this try-finally block does not have source lines associated and it was causing problems when the tracing functionality was running over it.