The existing code assumes that the number of inputs is fixed to 4.
However, the fuzzer says that at least 5 inputs are also possible.
This CL makes the number of inputs more flexible.

CC=sam.parker@arm.com

Bug: chromium:1197393
Change-Id: I487ac96570b96f04b4d0a47065e7b383ba39016f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2821435Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73917}