This required refactoring ParsePropertyDefinition to pass the parsed
string name as an out param, since ObjectLiteralProperty stores Smis
for Smi-representable property keys.

Computed properties are not yet handled in this patch.

BUG=v8:3699
LOG=n

Review URL: https://codereview.chromium.org/1563923002

Cr-Commit-Position: refs/heads/master@{#33141}