This makes sure the deoptimizer can materialize sloppy arguments objects
with the FAST_SLOPPY_ARGUMENTS_ELEMENTS elements kind. TurboFan's escape
analysis treates those as normal JSObject types and hence materializes
them differently than Crankshaft does.

R=verwaest@chromium.org
TEST=mjsunit/regress/regress-crbug-613919
BUG=chromium:613919

Review-Url: https://codereview.chromium.org/2001133002
Cr-Commit-Position: refs/heads/master@{#36440}