This makes --print-code and --print-wasm-code also print code emitted
on the native wasm heap.
It also extends code printing to include the code kind and the index.

R=mtrofin@chromium.org

Change-Id: I39c23f4b65168c059f23477ec5d264924ca83e82
Reviewed-on: https://chromium-review.googlesource.com/831987Reviewed-by: Mircea Trofin <mtrofin@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50166}