LSan is not implemented on windows, and trying to use the
{__lsan_ignore_object} function gives link error.
Since LSan is never enabled on windows, we also don't need the
annotations, so just disable them on windows.

R=bmeurer@chromium.org

Bug: chromium:842166,v8:7738
Change-Id: Ibaed77b4b884c09c7a08e081d953c56c53f907ff
Reviewed-on: https://chromium-review.googlesource.com/1056990Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53141}