Increase benchmark iterations to 100 and enhance flush method for Windows compatibility

cpp/src/Private/sweepstore/utils/file_handle.cpp

@@ -55,6 +55,7 @@ void SweepstoreFileHandle::close() {
 #endif
 }
 
+#if defined(_WIN32) || defined(WITH_UNREAL)
 // flush
 void SweepstoreFileHandle::flush() {
 #ifdef WITH_UNREAL
@@ -64,15 +65,12 @@ void SweepstoreFileHandle::flush() {
 #else
     if (stream) {
         stream->flush();
-#ifdef _WIN32
         // On Windows, also sync to ensure data hits disk
         stream->sync();
-#endif
     }
 #endif
 }
 
-#if defined(_WIN32) || defined(WITH_UNREAL)
 // readSeek
 void SweepstoreFileHandle::readSeek(std::streampos pos, std::ios::seekdir dir) {
 #ifdef WITH_UNREAL