Fix dart:io Process callback on Windows platfrom calling convention from cdecl to stdcall.

runtime/bin/process_win.cc

Index: runtime/bin/process_win.cc
diff --git a/runtime/bin/process_win.cc b/runtime/bin/process_win.cc
index ca4d1473f0d0c0a14f41160503c6d4c12d43f0b8..e9cab3055c75061c9287cda9293179ff7bd73dc7 100644
--- a/runtime/bin/process_win.cc
+++ b/runtime/bin/process_win.cc
@@ -74,7 +74,7 @@ class ProcessInfoList {
     BOOL success = RegisterWaitForSingleObject(
         &wait_handle,
         handle,
-        reinterpret_cast<WAITORTIMERCALLBACK>(ExitCodeCallback),
+        &ExitCodeCallback,
         reinterpret_cast<void*>(pid),
         INFINITE,
         WT_EXECUTEONLYONCE);
@@ -128,7 +128,7 @@ class ProcessInfoList {
  private:
   // Callback called when an exit code is available from one of the
   // processes in the list.
-  static void ExitCodeCallback(void* data, bool timed_out) {
+  static void CALLBACK ExitCodeCallback(PVOID data, BOOLEAN timed_out) {
     if (timed_out) return;
     DWORD pid = reinterpret_cast<DWORD>(data);
     HANDLE handle;