thread-local storage: c front end and generic backend patch

[Richard Henderson <rth at redhat dot com>]

The following adds support in the C front end for a new 
storage specifier keyword "__thread" that marks a variable
to be allocated in storage private to every extant thread.

A similar patch for the C++ front end will follow directly;
I wanted to split that out for ease of review by the C++
front end folk.

Joseph, the extend.texi documentation has some user-level
description of the extension.  I've tried to come up with
a set of edits for C99, but I'm not sure where to put them,
or exactly what form they should take.  Thoughts?

There is a fledgeling testsuite here, but it won't get run
until you have target support as well.  I have x86 support
completed, and it'll get submitted as soon as I clean it up
properly and add some autoconf detection logic for binutils
support.


r~

Attachment: tls-iso-changes
Description: Text document

Attachment: d-tls-32-1
Description: Text document