This adds support for dematerialized context values as part of an
interpreted frame (similar to an FCG frame). Both frame translations
should be kept in sync as much as possible.

R=rmcilroy@chromium.org
BUG=chromium:644728

Review-Url: https://codereview.chromium.org/2313343002
Cr-Commit-Position: refs/heads/master@{#39256}