Insert materialized context at the right place in DebugEvaluate.

R=aandrey@chromium.org, ulan@chromium.org
BUG=chromium:323936
LOG=N

Review URL: https://codereview.chromium.org/599113002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24218 ce2b1a6d-e550-0410-aec6-3dcde31c8c00