port ba2077aa (r34136)

  original commit message:
  Move the already existing fast case for %NewObject into a dedicated
  FastNewObjectStub that we can utilize in places where we would otherwise
  fallback to %NewObject immediately, which is rather expensive.

  Also use FastNewObjectStub as the generic implementation of JSCreate,
  which should make constructor inlining based on SharedFunctionInfo (w/o
  specializing to a concrete closure) viable soon.

BUG=

Review URL: https://codereview.chromium.org/1717203002

Cr-Commit-Position: refs/heads/master@{#34182}