Merge branch 'x86/mpx/prep' into x86/asm

Pick up some of the MPX commits that modify the syscall entry code,
to have a common base and to reduce conflicts.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --cc Makefile
Simple merge

diff --cc arch/x86/kernel/head_32.S
Simple merge

diff --cc arch/x86/kernel/head_64.S
Simple merge

diff --cc tools/objtool/check.c
Simple merge