Update locals()

[Brian Quinlan]

>   locals()
>   Return a dictionary representing the current local symbol table.
>   Warning: The contents of this dictionary should not be modified;
changes
>   may not affect the values of local variables used by the
interpreter.

The reason that changes to the locals dictionary might not be visible is
that LOAD_FAST instructions, which are used for local variable lookup,
use an indexed list and not the locals dictionary.

Cheers,
Brian