[Cython] [Bug] Don't compile lambda with tuple argument.

[yi huang]

λ $ cat /tmp/test.pyx
f = lambda (name,v):True

λ $ cython /tmp/test.pyx

Error compiling Cython file:
------------------------------------------------------------
...
f = lambda (name,v):True
                  ^
------------------------------------------------------------

/tmp/test.pyx:1:19: Empty declarator


Tested with both 0.21 and 0.23