This greens the wasm travis build.

BUG= https://code.google.com/p/v8/issues/detail?id=4203
TEST=asm-wasm tests
TBR=titzer@chromium.org,aseemgarg@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/1490673002

Cr-Commit-Position: refs/heads/master@{#32448}