Tamir Duberstein 8c61fc9ea6
integration-test: compile C probes using build.rs
- Add libbpf as a submodule. This prevents having to plumb its location
  around (which can't be passed to Cargo build scripts) and also
  controls the version against which codegen has run.
- Move bpf written in C to the integration-test crate and define
  constants for each probe.
- Remove magic; each C source file must be directly enumerated in the
  build script and in lib.rs.
..
bpf_probe_read.rs Clippy over tests and integration-ebpf
btf_relocations.rs Remove procfs dependency
elf.rs integration-test: Remove integration-test-macros
load.rs integration-test: compile C probes using build.rs
log.rs integration-test: Remove integration-test-macros
rbpf.rs integration-test: compile C probes using build.rs
relocations.rs integration-test: compile C probes using build.rs
smoke.rs integration-test: compile C probes using build.rs