Currently, v8 uses the same flag to collect time for instantiating wasm modules
from js asm and wasm. This separates the v8 counter into two separate counters,
and then uses the appropriate counter when instantiating a module.

BUG=chromium:704922
R=aseemgarg@chromium.org,bradnelson@chromium.org,bbudge@chromium.org

Review-Url: https://codereview.chromium.org/2772773004
Cr-Commit-Position: refs/heads/master@{#44122}