[wasm] Binary 11: Swap the order of section name / section length.
[wasm] Binary 11: Shorter section names.
[wasm] Binary 11: Add a prefix for function type declarations.
[wasm] Binary 11: Function types encoded as pcount, p*, rcount, r*
[wasm] Fix numeric names for functions.

R=rossberg@chromium.org,jfb@chromium.org,ahaas@chromium.org
BUG=chromium:575167
LOG=Y

Review-Url: https://codereview.chromium.org/1896863003
Cr-Commit-Position: refs/heads/master@{#35897}