Add tests with a few Array.of invocations in preparation for adding a
CodeStubAssembler generated version.

Change-Id: I5aee3f32a584ae31cebcbbe6b0e5491a4bc1da34
Reviewed-on: https://chromium-review.googlesource.com/861884Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50550}