Insert an overflow check when the sequence repetition count is outside the range of ints.  The old code would pass random truncated bits to sq_repeat() on a 64-bit machine.
Insert an overflow check when the sequence repetition count is outside
the range of ints.  The old code would pass random truncated bits to
sq_repeat() on a 64-bit machine.

Backport candidate.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator