Catalog: parallelize all-sky tile prefetch

src/frame.h

@@ -38,7 +38,9 @@ int frame_lens_mesh_trace(FrameLensMesh *mesh, const SpacetimeSource *spacetime,
 size_t frame_splat_catalog(const FrameLensMesh *mesh,
                            StarCatalog *catalog, double *hdr, int width,
                            int height, double exposure,
-                           const PointSpreadFunction *psf);
+                           const PointSpreadFunction *psf,
+                           int catalog_load_workers,
+                           CatalogPrefetchStats *prefetch_stats);
 void frame_draw_mesh(const FrameLensMesh *mesh, double *hdr, int width,
                      int height, double gray, double opacity);
 void frame_lens_mesh_destroy(FrameLensMesh *mesh);