This configuration causes /sys/kernel/btf/vmlinux to exist, which is
necessary for some eBPF programs (e.g. those that rely on the "BPF
CO-RE" feature; see
https://docs.kernel.org/bpf/libbpf/libbpf_overview.html for details).

The initial two patches introduce userland packages that enable building
the kernel with this configuration, and the third one changes the kernel
config.