GitLab

With this hb-view/hb-shape support pipes and possibly socket and named pipe
also, anything fails just on mmap.

We can later do the same for Windows also.

This however reveals two issues, the fact most of our bots don't have HAVE_MMAP and using
this instead the other fread/fopen reader can make failure on CI. I should look at them separately
this change however is very low risk I believe.