[m-rev.] for review: Disable detection of libhwloc by default.

[Julien Fischer]

On Thu, 17 May 2018, Peter Wang wrote:

> libhwloc is only used to support thread pinning in low-level C grades,
> an experimental (and IMHO dubious) feature that needs to be manually
> enabled via MERCURY_OPTIONS. On Linux, we also support thread pinning
> without libhwloc. In fact, when I tested it, thread pinning ONLY works
> without using libhwloc, so some code has probably bit-rotted.
>
> configure.ac:
>    Disable detection of libhwloc by default so we don't try to use it
>    just because it happens to be installed.

That's fine.

Julien.