an empty keywords dictionary (via apply() or the extended call syntax),
the keywords dict should be ignored. If the keywords dict is not empty,
TypeError should be raised. (Between the restructuring of the call
machinery and this patch, an empty dict in this situation would trigger
a SystemError via PyErr_BadInternalCall().)
Added regression tests to detect errors for this.
When a method is called with no regular arguments and * args, defer
the first arg is subclass check until after the * args have been
expanded.
N.B. The CALL_FUNCTION implementation is getting really hairy; should
review it to see if it can be simplified.
If a non-tuple sequence is passed as the *arg, convert it to a tuple
before checking its length.
If named keyword arguments are used in combination with **kwargs, make
a copy of kwargs before inserting the new keys.