For easier debugging of Liftoff code generation issues, add code
comments or out-of-line code.

The name is generated from the {RuntimeStubId}. The respective name
accessor is currently defined on the {NativeModule}, this CL makes it a
top-level function so we can reuse it from Liftoff.

R=thibaudm@chromium.org

Bug: v8:10235
Change-Id: I7b99779217b9c052e34ad132eb34859b20548092
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2134307
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66978}