[automerger skipped] Add libwinpthread-1.dll to windows sdk, copied from clang-r365631b am: 4f5f0234b6 am: a84a159a42 -s ours am: 15933fb063 -s ours am: 1eb61fa822 -s ours

am skip reason: Change-Id I53ff5f9769aa527cd340bc08cb494005428fc646 with SHA-1 67595976c2 is in history

Change-Id: Ibe234ffac819f37451531a70b87442ccc2c27c7f