Add instrumentation tooling

[ohmtech-rdi]

When an audio drop happens on the target platform, it is for now hard to understand the cause of that glitch.

It seems that there is no instrumentation tooling available to diagnose those kind of problems.

Implement an intrusive sampling method using a ring buffer on the stack, a way to detect an event (here an audio drop), and dump the data from the ring buffer using semihosting.