This fixes the lowering of Reflect.getPrototypeOf and friends to not
perform a [[ToObject]] coercion, but bailout instead. We ensure to
exclude primitive values from the lowering. This makes the lowering
uniform between "Reflect.getPrototypeOf" and "Object.getPrototypeOf".

R=bmeurer@chromium.org
TEST=mjsunit/regress/regress-crbug-740116
BUG=chromium:740116

Change-Id: If986ee2a3ae4e8f1fd227bdeb4668f523b0dea84
Reviewed-on: https://chromium-review.googlesource.com/565295Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46556}