This fixes the SharedFunctionInfo::num_literals field for global builtin
functions (e.g. {Object} and friends) to be accurate. The field was not
being updated by Runtime_SetCode. It also removes the dangerous and by
now obsolete JSFunction::NumberOfLiterals accessor.

R=mvstanton@chromium.org

Review-Url: https://codereview.chromium.org/2007943002
Cr-Commit-Position: refs/heads/master@{#36480}