Switch statements generate a counter for each clause plus a continuation
counter.

Bug: v8:6000
Change-Id: Ic55a7efda54de1152bd5283d753119aa2764afbd
Reviewed-on: https://chromium-review.googlesource.com/558249Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46550}