Another attempt to address the tracepoint ABI problem

There is already support for running a BPF program when an arbitrary kernel function is called, with access to that function's arguments -- this can be done using kprobes. Indeed, in BCC (https://github.com/iovisor/bcc) we have a large collection of BPF-based tools that rely on tracepoints when available, and kprobes when not. Over the last 1.5 years, we had multiple tools break because of intentional and unintentional changes to kernel functions when using kprobes; not so much when using tracepoints.