Fix T65330: Blender crash when double click on face

The fix itself is by Germano Cavalcante (mano-wii).

But since I was investigating this with him, I'm including here an
assert in EDBM_select_id_bm_elem_get to help catching this sooner
in the future

source/blender/draw/intern/draw_cache_impl_mesh.c

@@ -2757,7 +2757,7 @@ static void mesh_create_edit_facedots_select_id(MeshRenderData *rdata, GPUVertBu
       if (p_orig != ORIGINDEX_NONE) {
         const BMFace *efa = BM_face_at_index(rdata->edit_bmesh->bm, p_orig);
         if (!BM_elem_flag_test(efa, BM_ELEM_HIDDEN)) {
-          *((uint *)GPU_vertbuf_raw_step(&idx_step)) = poly;
+          *((uint *)GPU_vertbuf_raw_step(&idx_step)) = p_orig;
         }
       }
     }

source/blender/editors/mesh/editmesh_select.c

@@ -302,6 +302,11 @@ BMElem *EDBM_select_id_bm_elem_get(struct EDBMSelectID_Context *sel_id_ctx,
     }
   }
 
+  if (base_index >= sel_id_ctx->bases_len) {
+    BLI_assert(0);
+    return NULL;
+  }
+
   if (r_base_index) {
     *r_base_index = base_index;
   }