It's possible that we encounter incorrect SP or FP values while
unwinding the stack. One reason is that third-party code like virus
protection may change the stack. If we encounter values for SP or FP
that don't make sense, we should bail out of unwinding and return false.

Bug: v8:8116, chromium:909957
Change-Id: I630fef3f619382c7035be50b86072be349ed185c
Reviewed-on: https://chromium-review.googlesource.com/c/1358514Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58018}