Add a sanity check for inclusion of port_platform.h
diff --git a/src/core/lib/iomgr/ev_epoll1_linux.cc b/src/core/lib/iomgr/ev_epoll1_linux.cc
index f84f3f8..3ebaf18 100644
--- a/src/core/lib/iomgr/ev_epoll1_linux.cc
+++ b/src/core/lib/iomgr/ev_epoll1_linux.cc
@@ -16,6 +16,8 @@
  *
  */
 
+#include <grpc/support/port_platform.h>
+
 #include "src/core/lib/iomgr/port.h"
 
 #include <grpc/support/log.h>