Merge branch 'upstream-x86-selftests' into WIP.x86/pti.base

Documentation/x86/x86_64/mm.txt

arch/x86/Kconfig

arch/x86/entry/syscalls/Makefile

arch/x86/include/asm/cpufeatures.h

arch/x86/include/asm/pgtable_types.h

arch/x86/kernel/Makefile

arch/x86/kernel/cpu/cpuid-deps.c

arch/x86/kernel/head_64.S

arch/x86/mm/init_64.c

arch/x86/mm/kasan_init_64.c

arch/x86/xen/mmu_pv.c

include/linux/bitops.h

include/linux/mm.h

include/linux/mmzone.h

mm/gup.c

mm/page_alloc.c

mm/sparse.c

tools/testing/selftests/x86/ldt_gdt.c

tools/testing/selftests/x86/protection_keys.c