[$] An update on BPF generation from GCC

The generation of binary code for the kernel's BPF virtual machine has beenlimited to the Clang compiler since the beginning; even developers whouse GCC to build kernels must use Clang to compile to BPF. Work hasbeen underway for some years on adding a BPF backend to GCC as well; thedevelopers involved ran a session at the 2024 GNU Tools Cauldron toprovide an update on that project. It would seem that the BPF backend isclose to being ready for production use.