[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}

[wasm] Binary 11: br_table takes a value.
[wasm] Binary 11: Add implicit blocks to if arms.
[wasm] Binary 11: Add arities to call, return, and breaks
[wasm] Binary 11: Add experimental version.

This CL changes the encoder, decoder, and tests to use a postorder
encoding of the AST, which is more efficient in decode time and
space.

R=bradnelson@chromium.org,rossberg@chromium.org,binji@chromium.org
BUG=chromium:575167
LOG=Y

Review-Url: https://codereview.chromium.org/1830663002
Cr-Commit-Position: refs/heads/master@{#35896}

R=ahaas@chromium.org,binji@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1770913002

Cr-Commit-Position: refs/heads/master@{#34559}

R=binji@chromium.org,jfb@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1740373002

Cr-Commit-Position: refs/heads/master@{#34346}

R=binji@chromium.org,jfb@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1744713003

Cr-Commit-Position: refs/heads/master@{#34342}