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

Note: This CL doesn't separate the corresponding Chromium counter. Rather that is intenionally being delayed until v8 code has separated all appropriate counters for js asm and wasm. That way, the installation into chrome can be done at once.

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

Review-Url: https://codereview.chromium.org/2778493002
Cr-Commit-Position: refs/heads/master@{#44126}