Isolate::Dispose calls i::Isolate::TearDown, which again calls
i::Isolate::DumpAndResetCompilationStats.
We need this to be called on each exit path for dumping runtime call
stats.

R=cbruni@chromium.org, bmeurer@chromium.org

Review-Url: https://codereview.chromium.org/2694933004
Cr-Commit-Position: refs/heads/master@{#43215}