See https://github.com/mathiasbynens/es-regexp-unicode-property-escapes

Changes:
- only allow General Category, binary properties, Script, and Script_Extensions.
- implement Script_Extensions.

R=littledan@chromium.org
BUG=v8:4743

Review-Url: https://codereview.chromium.org/2502933002
Cr-Commit-Position: refs/heads/master@{#41091}