x86: merge irq_regs.h

Impact: cleanup, better irq_regs code generation for x86_64

Make 64-bit use the same optimizations as 32-bit.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --cc arch/x86/include/asm/irq_regs.h
Simple merge

diff --cc arch/x86/include/asm/irq_regs_32.h
Simple merge

diff --cc arch/x86/include/asm/irq_regs_64.h
Simple merge

diff --cc arch/x86/kernel/irq_64.c
Simple merge