If async function A awaited async function B, stepOut from function B
should go to function A.

Bug: v8:7753
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Iedc1d8b85a52aa60519e56b319325436fc2168c9
Reviewed-on: https://chromium-review.googlesource.com/1054618
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53451}