Upgrade Linux to 4.8 and adjust our kernel tweaks accordingly
* [amd64] Enable LEGACY_VSYSCALL_NONE instead of LEGACY_VSYSCALL_EMULATE. This breaks (e)glibc 2.13 and earlier, and can be reverted using the kernel parameter: vsyscall=emulate * Enable SLAB_FREELIST_RANDOM * security,printk: Enable SECURITY_DMESG_RESTRICT, preventing non-root users reading the kernel log by default (sysctl: kernel.dmesg_restrict)
Likely we can drop a couple tweaks we do, and should check if at least
slab_nomerge is still the best we can do.
Feature Branch: feature/11886-linux-4.8