aya/bpf
Dave Tucker 79101e748a test: Replace RTF with Rust
This commit replaces the existing RTF test runner with a simple rust
binary package called - integration-test.

integration-test depends on integration-ebpf, which contains test eBPF
code written in Rust and C. `cargo xtask build-integration-test-ebpf`
can be used to build this code and supress rust-analyzer warnings. It
does require `bpf-linker`, but that is highly likely to be available to
developers of Aya. It also requires a checkout of `libbpf` to extract
headers like bpf-helpers.h.

Since everything is compiled into a single binary, it can be run
be run locally using `cargo xtask integration-test` or remotely using
`./run.sh` which re-uses the bash script from the old test framework
to spawn a VM in which to run the tests.

Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
..
aya-bpf aya-bpf: use bpf_read_probe for reading pt_regs
aya-bpf-bindings bpf: re-reun build.rs if env changed
aya-bpf-cty bpf: re-reun build.rs if env changed
aya-bpf-macros bpf: Implement BPF_PROG_TYPE_CGROUP_SOCK
Cargo.toml bpf: add aya-bpf-bindings
rustfmt.toml test: Replace RTF with Rust