Initial version of a new StrictEqualStub written as TurboFan code stub,
that implements the full strict equality comparison and is usable for
both TurboFan and Ignition (and soon for the generic CompareIC case
too). The stub is not fully optimized yet, i.e. we still go to the
runtime for string comparisons, but that'll be addressed in a follow-up
CL.

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/1753173003

Cr-Commit-Position: refs/heads/master@{#34423}