Fix compilation issues on systems without std::filesystem (#23)

src/rocjpeg_vaapi_decoder.cpp

@@ -499,7 +499,11 @@ void RocJpegVappiDecoder::GetVisibleDevices(std::vector<int>& visible_devices_ve
 void RocJpegVappiDecoder::GetCurrentComputePartition(std::vector<ComputePartition> &current_compute_partitions) {
     std::string search_path = "/sys/devices/";
     std::string partition_file = "current_compute_partition";
+#if __cplusplus >= 201703L && __has_include(<filesystem>)
     for (const auto& entry : std::filesystem::recursive_directory_iterator(search_path)) {
+#else
+    for (const auto& entry : std::experimental::filesystem::recursive_directory_iterator(search_path)) {
+#endif
         if (entry.path().filename() == partition_file) {
             std::ifstream file(entry.path());
             if (file.is_open()) {

src/rocjpeg_vaapi_decoder.h

@@ -31,7 +31,11 @@ THE SOFTWARE.
 #include <string>
 #include <fcntl.h>
 #include <unistd.h>
-#include <filesystem>
+#if __cplusplus >= 201703L && __has_include(<filesystem>)
+    #include <filesystem>
+#else
+    #include <experimental/filesystem>
+#endif
 #include <unordered_map>
 #include <memory>
 #include <va/va.h>