test-sampler-api.cc calls {Simulator::get_pc} and
{Simulator::get_register}, hence these methods need to be exported.

R=ahaas@chromium.org

Change-Id: I5ba48d877f7101d1e8527c8138fa2e930ba686ab
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1611678Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61478}