Wide suspends have a "wide" (or "extra-wide") bytecode at their offset,
rather than the suspend itself, so they were failing the return check.

Bug: chromium:805765
Change-Id: Iabfc2a2167d09eda2f6885d9100287aadcd8fee9
Reviewed-on: https://chromium-review.googlesource.com/887082Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50923}