Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

gcc: Add support for label attributes and "unavailable" attribute.

Apple GCC has extensions to support for both label attributes and
an "unavailable" attribute. These are critical for objc but are
also useful in regular C/C++.

Apparently at least the label attributes might have found their way to
upstream GCC but the code doesn't seem available on the GPLv2 tree so
we are taking the code directly from Apple. To make this clearer we
are preserving the annoying "APPLE LOCAL" tags and the ChangeLogs
when they are available.

Obtained from: Apple GCC 4.2 - 5531
MFC after: 3 weeks

This commit was generated by cvs2svn to compensate for changes in r169689,
which included commits to RCS files with non-trunk default branches.

GCC 4.2.0 release.

Gcc 3.4.2 20040728.

Gcc 3.3.1-pre as of 2003-07-11.

Gcc 3.1.0 pre-release from the FSF anoncvs repo on 9-May-2002 15:57:15 EDT.

Enlist the FreeBSD-CURRENT users as testers of what is to become Gcc 3.1.0.
These bits are taken from the FSF anoncvs repo on 1-Feb-2002 08:20 PST.