This should fix one of the arm64 build breaks - we have tried to mark
half-initialized native context there, but the normalized_map_cache
entry was still undefined.

R=hpayer@chromium.org
BUG=

Review URL: https://codereview.chromium.org/284633002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21283 ce2b1a6d-e550-0410-aec6-3dcde31c8c00