Prior to this change, both 0 and 1 as RNG seed would result in the same
internal state. state0 and state1 cannot both be zero, but murmur hash
maps 0 back to 0.

R=cbruni@chromium.org
BUG=v8:5069

Review-Url: https://codereview.chromium.org/2040953002
Cr-Commit-Position: refs/heads/master@{#36757}