port 2fc2cb99 (r32144)

  original commit message:
  The old code was not ready for properly initialize objects with non standard headers and non zero in-object properties number.

  MacroAssembler::Allocate() implementations now return both start and end addresses of the new object (done by parameter renaming).

BUG=

Review URL: https://codereview.chromium.org/1467923002

Cr-Commit-Position: refs/heads/master@{#32161}