[win32] integrate mainline

p4raw-id: //depot/win32/perl@588

diff --cc dosish.h
Simple merge

diff --cc t/lib/thread.t
index 9810ae4,b8e1b38..b8e1b38
mode 100644,100755..100644
--- 1/t/lib/thread.t
--- 2/t/lib/thread.t
+++ b/t/lib/thread.t

diff --cc t/op/nothread.t
index 7d42d27,a0d444d..a0d444d
mode 100644,100755..100644
--- 1/t/op/nothread.t
--- 2/t/op/nothread.t
+++ b/t/op/nothread.t