[RFC][gdbsupport] Add PARALLEL_FOR_EACH_DEBUG

[Tom Tromey]

>>>>> "Tom" == Tom de Vries via Gdb-patches <gdb-patches@sourceware.org> writes:

Tom> +#define PARALLEL_FOR_EACH_DEBUG 0

Probably needs a short comment.

Tom> +#if PARALLEL_FOR_EACH_DEBUG
Tom> +  fprintf (stderr, "Parallel for: n_elements: %zu\n", n_elements);
Tom> +  fprintf (stderr, "Parallel for: minimum elements per thread: %u\n", n);

I'm meh on this kind of logging but if it helped you it seems fine.

Tom