[feature] add raw pointer access to tilings

Same reasons as for aml_layout_rawptr.
Note that deref only works because we can be sure that none of our
tilings have padding or dummy data at the beginning of a tile. Otherwise
we would need to do a real index + rawptr on it, and clean up the layout
after.

tiling style
6 jobs for rawptr in 3 minutes and 16 seconds (queued for 1 second)
Status Job ID Name Coverage
  Style
passed #55473
nix kvm
checkpatch

00:00:14

passed #55472
nix kvm
repoquality

00:00:02

passed #55474
nix kvm
style:docs

00:00:25

 
  Build
passed #55475
nix kvm
make:generic

00:00:34

passed #55477
knl
make:knl

00:02:48

passed #55476
nix kvm
make:out-of-tree

00:00:37