Make the various iterators' "setstate" sliently and consistently clip the

index.  This avoids the possibility of setting an iterator to an invalid
state.

diff --cc Lib/test/test_range.py
Simple merge

diff --cc Modules/arraymodule.c
Simple merge

diff --cc Objects/bytearrayobject.c
Simple merge

diff --cc Objects/bytesobject.c
Simple merge

diff --cc Objects/listobject.c
Simple merge

diff --cc Objects/rangeobject.c
Simple merge

diff --cc Objects/tupleobject.c
Simple merge

diff --cc Objects/unicodeobject.c
Simple merge