Deoptimization may materialize values on the heap, which may get sampled
by the heap profiler. Such samples have imprecise stack. Indicate this.

BUG=v8:7314

Change-Id: I21ab079c36fc0492b05b546cc1d6a8e6c042aeb8
Reviewed-on: https://chromium-review.googlesource.com/877119
Commit-Queue: Ali Ijaz Sheikh <ofrobots@google.com>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50775}