With --harmony-function-tostring enabled (now enabled by --harmony),
CompileFunctionInContext would produce incorrect results whenever called
with 1 or more argument parameters, due to specifying an incorrect end
position for the parameters.

BUG=v8:6190, v8:4958
R=littledan@chromium.org, adamk@chromium.org, jwolfe@igalia.com

Change-Id: Ied2bcba44116311ebcae3967963472b4e1058fd3
Reviewed-on: https://chromium-review.googlesource.com/465515
Commit-Queue: Caitlin Potter <caitp@igalia.com>
Reviewed-by: Daniel Ehrenberg <littledan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44340}