[PATCH bpf-next 3/8] libbpf: further decouple feature checking logic from bpf_object

[Eduard Zingerman]

> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index a6b8d6f70918..af5e777efcbd 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -637,6 +637,7 @@ struct elf_state {
>  };
>  
>  struct usdt_manager;
> +struct kern_feature_cache;

Nit: this forward declaration is not necessary.