SkRasterPipeline_opts: split next() into next_body() and next_tail().

This may work around an Chrome/MSVC/PGO compiler crasher.
Even if not, it's harmless for performance, and arguably more readable.

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=3789

Change-Id: I0bf23f65d7832b9f43e275f85e7985fcd6b13b9f
Reviewed-on: https://skia-review.googlesource.com/3789
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Mike Klein <mtklein@chromium.org>
1 file changed