Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Upgrade our copy of llvm/clang to trunk r178860, in preparation of the
upcoming 3.3 release (branching and freezing expected in a few weeks).

Preliminary release notes can be found at the usual location:
<http://llvm.org/docs/ReleaseNotes.html>

An MFC is planned once the actual 3.3 release is finished.

Upgrade our copy of llvm/clang to trunk r162107. With thanks to
Benjamin Kramer and Joerg Sonnenberger for their input and fixes.

Upgrade our copy of llvm/clang to r142614, from upstream's release_30
branch. This brings us very close to the 3.0 release, which is expected
in a week or two.

MFC after: 1 week

Vendor import of llvm release_30 branch r142614:
http://llvm.org/svn/llvm-project/llvm/branches/release_30@142614