Fix compile on windows: O_SYNC is not available, use a my_sync() call instead.

storage/rocksdb/rdb_utils.cc

@@ -358,7 +358,8 @@ bool rdb_check_rocksdb_corruption() {
 
 void rdb_persist_corruption_marker() {
   const std::string &fileName(myrocks::rdb_corruption_marker_file_name());
-  int fd = my_open(fileName.c_str(), O_CREAT | O_SYNC, MYF(MY_WME));
+  /* O_SYNC is not supported on windows */
+  int fd = my_open(fileName.c_str(), O_CREAT | IF_WIN(0, O_SYNC), MYF(MY_WME));
   if (fd < 0) {
     sql_print_error("RocksDB: Can't create file %s to mark rocksdb as "
                     "corrupted.",
@@ -370,6 +371,12 @@ void rdb_persist_corruption_marker() {
                           fileName.c_str());
   }
 
+#ifdef _WIN32
+  /* A replacement for O_SYNC flag above */
+  if (fd >= 0)
+    my_sync(fd, MYF(0));
+#endif
+
   int ret = my_close(fd, MYF(MY_WME));
   if (ret) {
     // NO_LINT_DEBUG