Following up on adding n-ary nodes, this extends the parser and
interpreter to support n-ary logical operations.

Bug: v8:6964
Bug: chromium:731861
Change-Id: Ife2141c389b9abccd917ab2aaddf399c436ef777
Reviewed-on: https://chromium-review.googlesource.com/735497Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49029}