Port ab9e0124

Original Commit Message:

    Original CL: https://crrev.com/c/1018468

    During code generation, we generate self-references (i.e. references to
    the Code object currently being generated) as references to a temporary
    handle. When the final Code object has been allocated, the handle's
    location is fixed up and RelocInfo iteration fixes up all references
    embedded in the generated code.

    This adds support for this mechanism to the builtins constants table
    builder. CodeObject() is now a new handle pointing to a dedicated
    self-reference marker in order to distinguish between self-references
    and references to undefined. In Factory::NewCode, we patch up
    the constants table.

R=jgruber@chromium.org, joransiu@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Change-Id: Iba0f4435125b9d6c3fda7fc3e9836494b6eb6f45
Reviewed-on: https://chromium-review.googlesource.com/1042216Reviewed-by: Joran Siu <joransiu@ca.ibm.com>
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#52969}