centralize and force-inline unaligned_{load,store}

We've got slightly different implementations of unaligned_load(), and
that's causing a x86 Chromium Debug builds to go a bit haywire.  A
single best implementation with an SK_ALWAYS_INLINE and explanation
should help things.

Might as well move its companion unaligned_store() too.

Bug: chromium:974542
Change-Id: If9f3eb4d33bfb8390c661f9e196122da0b9b84ca
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/221409
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Mike Klein <mtklein@google.com>
4 files changed