Redo our build flags, specifically: DONE

• Only set -fdata-sections and -ffunction-sections in relation to LTO setting (and size/speed optimisation)
• Drop -fexceptions (code bloat)
• Drop -fno-omit-frame-pointer (code bloat, performance, lost a register)
• Swap -fstack-protector --param ssp-buffer-size=32 for -fstack-protector-strong (covers the usual cases and isn't too aggressive)
• Fix ypkg to support optional LTO on clang builds
• Consider dropping -copy-dt-needed-entries due to gold borkage
• Consider defaulting to ld.gold when using lto optimisation
• Consider -Wl,-Bsymbolic-functions (-Bsymbolic by itself seems to have the potential for function pointer issues) to improve .so performance

Kernel: DONE

• Backport libata power management fix (patch)
• Update kernels - drag in some new turbo (3.0) patches

Misc: DONE

• Convert mesa to ypkg (pull from runtime-snaps) - for now move the LDM trigger into kernel-glue (absorb later into usysconf) (LTO, speed optimisations)
• Add more items after next sleep.