Add some owners to interpreter

Adds the following owners to interpreter/ directory:
 - oth@chromium.org
 - mstarzinger@chromium.org
 - bmeurer@chromium.org

Also sets noparent on the directory.

Review URL: https://codereview.chromium.org/1374533005

Cr-Commit-Position: refs/heads/master@{#31088}

src/interpreter/OWNERS

+set noparent
+
+bmeurer@chromium.org
+mstarzinger@chromium.org
+oth@chromium.org
 rmcilroy@chromium.org