sbcl-0.7.12 released

Version 0.7.12 of SBCL has been released. As usual, the source tarball
is available immediately, plus this time the OpenBSD binary I
generated, but other binaries are generated by others and come out
later.

This is a minor maintenance release, as reflected in the length of
the NEWS file entry.

This version is known to be completely broken for Alpha CPUs. (It
can't even build itself.) We have a fix for the problem -- currently
available as a patch on the sbcl-devel mailing list -- but both the
problem and the fix were found quite late in the release cycle, and we
don't quite understand all the issues involved, so I didn't merge the
patch into the current release.

Incidentally, the same Alpha brokenness also afflicts 0.7.11, so all
you Alpha users out may need to speak up more promptly when we ship
stuff that breaks on 64 bit architectures where SBCL still pretends to
be 32 bits.

from the NEWS file:
changes in sbcl-0.7.12 relative to sbcl-0.7.11:
  * minor incompatible change: code processed by the "interpreter" or
    EVAL now has a compilation optimization policy of (DEBUG 2)
    (changed from (DEBUG 1)) to improve debuggability of interactive
    development, and to allow the use of the debug RETURN command in
    such code.
  * an experimental implementation of the RETURN command for the
    debugger has been included.  (thanks to Frederik Kuivinen)
  * fixed bug 62: constraints were not propagated into a loop.