vo_gpu_next: forwards compatibility with pl_cache

Interrim solution, forwards compatible with new and backwards compatible
with old API. Eventually, we will want to discontinue the use of
deprecated pl_icc_params.save/load and pl_renderer_save/load, but that
requires minimum version bump.

video/out/vo_gpu_next.c

@@ -147,6 +147,10 @@ struct priv {
     pl_tex *sub_tex;
     int num_sub_tex;
 
+#if PL_API_VER >= 320
+    pl_cache cache;
+#endif
+
     struct mp_rect src, dst;
     struct mp_osd_res osd_res;
     struct osd_state osd_state;
@@ -1625,6 +1629,15 @@ static int preinit(struct vo *vo)
     ra_hwdec_ctx_init(&p->hwdec_ctx, vo->hwdec_devs, gl_opts->hwdec_interop, false);
     pthread_mutex_init(&p->dr_lock, NULL);
 
+#if PL_API_VER >= 320
+    p->cache = pl_cache_create(pl_cache_params(
+        .log = p->pllog,
+        .max_object_size =  1 << 20, //  1 MB
+        .max_total_size  = 10 << 20, // 10 MB
+    ));
+    pl_gpu_set_cache(p->gpu, p->cache);
+#endif
+
     p->rr = pl_renderer_create(p->pllog, p->gpu);
     p->queue = pl_queue_create(p->gpu);
     p->osd_fmt[SUBBITMAP_LIBASS] = pl_find_named_fmt(p->gpu, "r8");