Create a function table for State::syncDirtyObjects to avoid the
costly switch and inline calls along the Context::syncDirtyObjects
calling hierarchy.

Bug: angleproject:2975

Change-Id: I1ec797452af41bc767578e4017c8eccb7d83628b
Reviewed-on: https://chromium-review.googlesource.com/c/1340222
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>