Port d3ed71ed

Original Commit Message:

    Don't fallback to the %StrictEqual / %Equal runtime functions for the
    generic CompareIC slow path, but use the (new) StrictEqual and Equal
    builtins instead. This avoids a performance cliff when mixing input
    types for strict equality sites.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=v8:4773
LOG=N

Review-Url: https://codereview.chromium.org/2608283002
Cr-Commit-Position: refs/heads/master@{#42039}