In the JSInliner we shouldn't introduce JSConvertReceiver needlessly if
the input is already known to produce a receiver, i.e. if it's a
JSCreate or something like that.

BUG=v8:5267
R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2697513010
Cr-Commit-Position: refs/heads/master@{#43273}