There is a clear mistake of using kWasmF64 instead of kWasmF32.

R=ahaas@chromium.org

Change-Id: I638d568b3736fdb8417f17bcd04d17268a45b965
Reviewed-on: https://chromium-review.googlesource.com/939178Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51595}