Before, it was a method in wasm namespace, and received a
Handle<WasmCompiledModule>. As it does not allocate on the heap, we can
just make it a non-static method on WasmCompiledModule.

R=titzer@chromium.org

Review-Url: https://codereview.chromium.org/2536373007
Cr-Commit-Position: refs/heads/master@{#41429}