This is a stupid/trivial patch. I didn't realise when adding
htools-hpc that this will "break" tab completion on htools; as in, I
will have to add / manually always when completing files on the
command line.

So to fix my laziness, let's rename htools-hpc to hpc-htools,
eliminating this completion conflict.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>

This allows the offline tests to also generate coverage data, and the
hs-coverage target is changed to show both unit-test and offline-tests
coverage.

The downside is that now we build yet-another-binary, which makes the
unit-test time slower…

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>