This switches all uses of the patching {ToBooleanICStub} over to the
existing and non-patching {ToBoolean} CSA-builtin, and removes some
supporting code.

R=verwaest@chromium.org
BUG=v8:6408

Change-Id: Iab60c95e6b54e426408390e056b679f6227e7ce0
Reviewed-on: https://chromium-review.googlesource.com/539576Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46089}