The clusterfuzz issue crashes because VisitBinops expected only but 4
input operands but in the generated graph 5 input operands get created
The issue is fixed by increasing the size of the input operand buffer.

R=jarin@chromium.org

Bug: chromium:842501
Change-Id: I4bbb09a968e165e6f5a0a02d06eee97333f7aa38
Reviewed-on: https://chromium-review.googlesource.com/1056989Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53147}