BUG_ON enhancements, remove MAYBE_BUILD_BUG_ON.

Hi Linus,

These have been sitting in linux-next for several releases; this makes
BUG_ON cover a wider range of cases, and removes MAYBE_BUILD_BUG_ON which can fail entirely. Also adds some docs for BUG_ON.

The following changes since commit 1bae4ce27c9c90344f23c65ea6966c50ffeae2f5:

Linux 2.6.38-rc2 (2011-01-21 19:01:34 -0800)

are available in the git repository at:
ssh://master.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus.git BUG_ON

Rusty Russell (2):
BUILD_BUG_ON: make it handle more cases
Remove MAYBE_BUILD_BUG_ON

 include/linux/gfp.h           |    2 +-
 include/linux/kernel.h        |   32 ++++++++++++++++++++++++++------
 include/linux/kmemcheck.h     |    2 +-
 include/linux/virtio_config.h |    5 ++++-
 4 files changed, 32 insertions(+), 9 deletions(-)