4.15-stable patches

4.15-stable patches

added patches:
	compiler-gcc.h-__nostackprotector-needs-gcc-4.4-and-up.patch
	compiler-gcc.h-introduce-__optimize-function-attribute.patch
	crypto-sun4i_ss_prng-convert-lock-to-_bh-in-sun4i_ss_prng_generate.patch
	crypto-sun4i_ss_prng-fix-return-value-of-sun4i_ss_prng_generate.patch
	kvm-nvmx-set-the-cpu_based_use_msr_bitmaps-if-we-have-a-valid-l02-msr-bitmap.patch
	kvm-x86-reduce-retpoline-performance-impact-in-slot_handle_level_range-by-always-inlining-iterator-helper-methods.patch
	powerpc-mm-radix-split-linear-mapping-on-hot-unplug.patch
	revert-x86-speculation-simplify-indirect_branch_prediction_barrier.patch
	x86-entry-64-clear-extra-registers-beyond-syscall-arguments-to-reduce-speculation-attack-surface.patch
	x86-entry-64-compat-clear-registers-for-compat-syscalls-to-reduce-speculation-attack-surface.patch
	x86-mm-pti-fix-pti-comment-in-entry_syscall_64.patch
	x86-nvmx-properly-set-spec_ctrl-and-pred_cmd-before-merging-msrs.patch
	x86-speculation-clean-up-various-spectre-related-details.patch
	x86-speculation-correct-speculation-control-microcode-blacklist-again.patch
	x86-speculation-update-speculation-control-microcode-blacklist.patch