Trying to reland http://crrev.com/1974293002.

This time some blocks have been shuffled around in the AddStub so that the frame still doesn't get built for the fast path.

Also disables the DCHECK(!is_default_snapshot) in snapshot-common.cc if --debug-code is specified. This was causing cctest to fail on arm64 debug builds.

Review-Url: https://codereview.chromium.org/1980333002
Cr-Commit-Position: refs/heads/master@{#36279}