Unexec and Pure Storage removal

Unexec and Pure Storage removal

[Pip Cet]

Hello everyone,

I've just deleted-and-repushed the scratch/no-purespace branch: it
contains a series of commits removing unexec and pure storage.  These
are not meant to result in buildable intermediate versions of Emacs;
they're split up mostly because that makes it easier for me to work on
them.

Please, everyone, feel free to push to that branch (or otherwise submit)
changes you would like to see; I'm planning to rebase the branch (at
least) once more and obtain a version that, I hope, will be ready to be
merged into master.  However, of course, the final decision on that is
not mine to make and it should go without saying that I fully accept a
chance that it won't happen this year after all.

In particular, I welcome any comments on the commit messages' (or commit
message's) wording, style, and verbosity level.  I confess that my
priority was to provide a branch that people can look at and discuss,
and that happens to work on GNU/Linux systems, rather than taking
forever polishing something that might be rejected after all.

My apologies for not being able to do more than what I'm sure some will
consider a sloppy job, but I think it's important to share code that
works at least on one system today.

Again, with the usual caveats about paperwork, feel free to just change
things you dislike.  In the unlikely case that I disagree strongly, we
can always prepare multiple proposed patch series for inclusion and have
the maintainers choose one of them :-)  Of course, you can also discuss
them by email if you prefer.

The W32 part, I'm afraid, is currently completely untested.  I'll look
into changing that once I've had a break...

Pip