Macro readings_probe::instrumented_allocator

macro_rules! instrumented_allocator {
    () => { ... };
}

Setup global allocator instrumentation, to track rust-managed memory.

It is not mandatory to do so, as we also register the RSZ and VSZ as reported by the OS, but it may be interesting. From our experience it may be worth activating it as the cost is relatively modest.

This macro wrap the System allocator. Use wrap_global_allocator to wrap another global allocator.