The former will handle stores to global variables, lets and undeclared
variables. The latter will handle named stores to explicit receiver.

BUG=chromium:576312, v8:5561

Change-Id: I335fa21db47c3d001da8cc79fa8cb6f8abcbb7e2
Reviewed-on: https://chromium-review.googlesource.com/458639Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44085}