Identify wasm-to-wasm wrappers separately from wasm-to-js ones.

Bug: 
Change-Id: I853ed8fb999297f8a951ebb0e5be1c99bfacc18c
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/782680Reviewed-by: Brad Nelson <bradnelson@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Mircea Trofin <mtrofin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49580}