This relands this, in it's new home:
https://github.com/WebAssembly/v8-native-prototype/commit/032faa8a902f6555980e8848ca28208b0333d974

R=titzer@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1522473002

Cr-Commit-Position: refs/heads/master@{#32798}