Right now we manually make these files. We should make this part of the DerivedSources.make script. This won't be sustainable long term.
Created attachment 293397 [details] Patch
This patch modifies one of the wasm.json files. Please ensure that any changes in one have been mirrored to the other. You can find the wasm.json files at "Source/JavaScriptCore/wasm/wasm.json" and "JSTests/wasm/wasm.json".
Committed r208148: <http://trac.webkit.org/changeset/208148>