Explicitly merging these two branches due to nontrivial conflicts and
to allow further work.
Resolved Conflicts:
arch/x86/kernel/head32.c
arch/x86/kernel/head64.c
arch/x86/mm/init_64.c
arch/x86/realmode/init.c
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>