This CL simplifies the relation between the wasm graph builder, the
wasm decoder, and the wasm module they work on.
BUG=
Review-Url: https://codereview.chromium.org/2612643002
Cr-Commit-Position: refs/heads/master@{#42056}
This is more renaming work to comply with the naming in the public
design repository. E.g. types are called "value types" and we no longer
refer to ASTs.
R=clemensh@chromium.org
BUG=
Review-Url: https://codereview.chromium.org/2594993002
Cr-Commit-Position: refs/heads/master@{#41891}