Port 46d0e481

Original Commit Message:

    The CallApiCallbackStub can avoid loading undefined in case the
    call_data is already undefined, which doubles the number of versions of
    the stub and adds unnecessary complexity (at the benefit of saving one
    stupid load). The idea is to turn the CallApiCallbackStub into a single
    builtin instead, which does the right thing, so this is the first step
    towards that goal.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=v8:6304
LOG=N

Review-Url: https://codereview.chromium.org/2837283004
Cr-Commit-Position: refs/heads/master@{#44872}