add a check-tsan-shared in cmake.sh
The patch itself is LGTM but we can't land it. "ninja tsan-shared" and "ninja check-tsan-shared" do not work in the HEAD and in D108394. We need to add them into cmake files before adding to the buildbot.
Also, let's call the target "tsan-dynamic" to match the naming convention established in asan.
LGTM, but please wait day or so after landing D108394