In the asm.js to wasm pipeline, we generate an entry function with
BUILTIN code, but still attached to a TYPE_NORMAL script.
This fix avoids trying to set a breakpoint there, resulting in a crash
on DCHECK(shared->HasDebugInfo()).

Also add two inspector tests to track regressions.

BUG=v8:5568
R=titzer@chromium.org,mstarzinger@chromium.org

Review-Url: https://codereview.chromium.org/2457433002
Cr-Commit-Position: refs/heads/master@{#40633}