Merged r19594 into 3.24 branch.

Fix handling of constant global variable assignments.

BUG=347904
LOG=N
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/186623002

git-svn-id: https://v8.googlecode.com/svn/branches/3.24@19653 ce2b1a6d-e550-0410-aec6-3dcde31c8c00