bpo-31334: Fix timeout in select.poll.poll() (GH-3277)

Always pass -1, or INFTIM where defined, to the poll() system call when
a negative timeout is passed to the poll.poll([timeout]) method in the
select module. Various OSes throw an error with arbitrary negative
values.
diff --git a/Misc/ACKS b/Misc/ACKS
index 38f68ac..8b9f62e 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -292,6 +292,7 @@
 Robbie Clemons
 Steve Clift
 Hervé Coatanhay
+Riccardo Coccioli
 Nick Coghlan
 Josh Cogliati
 Dave Cole
diff --git a/Misc/NEWS.d/next/Library/2017-09-04-00-22-31.bpo-31334.9WYRfi.rst b/Misc/NEWS.d/next/Library/2017-09-04-00-22-31.bpo-31334.9WYRfi.rst
new file mode 100644
index 0000000..1cbfd25
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2017-09-04-00-22-31.bpo-31334.9WYRfi.rst
@@ -0,0 +1,3 @@
+Fix ``poll.poll([timeout])`` in the ``select`` module for arbitrary negative
+timeouts on all OSes where it can only be a non-negative integer or -1.
+Patch by Riccardo Coccioli.