Cancel pending i/o when closing stdin on Windows

runtime/bin/eventhandler_win.cc

Index: runtime/bin/eventhandler_win.cc
diff --git a/runtime/bin/eventhandler_win.cc b/runtime/bin/eventhandler_win.cc
index 81adcfdf4f582c629c78b8d7473d538c11ca9bbe..2cecd77f1c56280d3f9d3bd4a65f0cef1b3f0d93 100644
--- a/runtime/bin/eventhandler_win.cc
+++ b/runtime/bin/eventhandler_win.cc
@@ -145,6 +145,12 @@ bool Handle::CreateCompletionPort(HANDLE completion_port) {
 
 
 void Handle::Close() {
+  if (!SupportsOverlappedIO()) {
+    // If the handle uses synchronous I/O (e.g. stdin), cancel any pending
+    // operation before closing the handle, so the read thread is not blocked.
+    BOOL result = CancelIoEx(handle_, NULL);
+    ASSERT(result);
+  }
   MonitorLocker ml(monitor_);
   if (!IsClosing()) {
     // Close the socket and set the closing state. This close method can be