With this CL we reduce the difference between directly using a null prototype
in a literal or using Object.create(null).
- The EmitFastCloneShallowObject builtin now supports cloning slow
  object boilerplates.
- Unified behavior to find the matching Map and instantiating it for
  Object.create(null) and literals with a null prototype.
- Cleanup of literal type parameter of CompileTimeValue, now in sync with
  ObjectLiteral flags.

Review-Url: https://codereview.chromium.org/2445333002
Cr-Commit-Position: refs/heads/master@{#44941}