Both labeled blocks:

l0: { break l0; }

and blocks containing jump statements (break, return, continue) require a
continuation counter to correctly display coverage.

Bug: v8:6000
Change-Id: I3ae8ddd3d9f6c087622482b86014dd583b774b71
Reviewed-on: https://chromium-review.googlesource.com/568024Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46644}