When ASAN is enabled, the previous implementation of
Isolate::GetIncumbentContext didn't work well due to mixture of fake
and real stack frames.

This patch converts an address in the fake stack frame to an address
in the real stack frame so that we can compare two addresses.

Bug: chromium:888867, chromium:866610
Change-Id: Iccf570b8555f2fbdc737b12894a2784ffdb31602
Reviewed-on: https://chromium-review.googlesource.com/c/1343709Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Yuki Shiino <yukishiino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57662}