Fix condition in declare_cpp_class

The profiler filters lines on the function's __code__ attribute, which
must agree with that created in the profile frame.  Unfortunately, this
makes it difficult to profile anything but 'def' functions.

Condition is no longer valid since commit fa3db367

always create a new IntNode for the step value in iter-range optimisation as we overwrite its value later

Optimized reversed range with constant negative steps.

extend reversed iteration tests, including disabled tests for negative step values that fail when enabled

--HG--
extra : transplant_source : %F9%BB%B7%FD%A5jc%89%02%BD%BANie%A3%FDc%8F%9Ct

Use PySequence_List, PySequence_Tuple

Cython array import naming conflict

do not depend on reversed(range()) bounds having a numeric type and just use whatever spanning type we find

Optimized reversed-range call when constants are inside of the range.