Add the operator in preparation for actual perf work. The operator is replaced
by the same runtime call as before, during lowering.

The CallConstructWithSpreadParameters is a bit silly at the moment, but will
hold more once we add feedback.

BUG=v8:5659

Review-Url: https://codereview.chromium.org/2561103003
Cr-Commit-Position: refs/heads/master@{#41636}