Copy pollset_posix to pollset_windows
diff --git a/build.json b/build.json
index 9a5134e..40572f2 100644
--- a/build.json
+++ b/build.json
@@ -49,6 +49,7 @@
         "src/core/iomgr/pollset_kick.h",
         "src/core/iomgr/pollset_kick_posix.h",
         "src/core/iomgr/pollset_posix.h",
+        "src/core/iomgr/pollset_windows.h",
         "src/core/iomgr/resolve_address.h",
         "src/core/iomgr/sockaddr.h",
         "src/core/iomgr/sockaddr_posix.h",
@@ -126,6 +127,7 @@
         "src/core/iomgr/pollset_kick_posix.c",
         "src/core/iomgr/pollset_multipoller_with_poll_posix.c",
         "src/core/iomgr/pollset_posix.c",
+        "src/core/iomgr/pollset_windows.c",
         "src/core/iomgr/resolve_address_posix.c",
         "src/core/iomgr/sockaddr_utils.c",
         "src/core/iomgr/socket_utils_common_posix.c",