* Rename BoilerplateDescription to ObjectBoilerplateDescription
* Add literal_type flag to ObjectBoilerplateDescription,
  which is stored as zeroth element of Fixed array
* Create ArrayBoilerplateDescription with elements_kind and
  constant_elements field
* Replace CompileTimeValue and ConstantElementPair with
  ArrayBoilerplateDescription
* Kill ConstantElementPair and CompileTimeValue

Change-Id: Icb42dcfd575a27e2b64ffd5e2e61f9d703d5e986
Bug: v8:7787, chromium:818642
Reviewed-on: https://chromium-review.googlesource.com/1122411
Commit-Queue: Chandan Reddy <chandanreddy@google.com>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54272}