Also takes care of InterpreterEnterBytecodeAdvance.

Drive-by:
 - Add DCHECK to ensure cmpb is only used with byte registers.
 - Add Push/PopRootRegister to TurboAssembler with DCHECK ensuring
   that there is a NoRootArrayScope


Change-Id: Ibcf1c91b12767bdf6425b18872c41b31124de3ba
Bug: v8:6666
Reviewed-on: https://chromium-review.googlesource.com/1190305Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55512}