What in the name of all that's angled or curly does WebAssembly have to do with C/C++ ?
WebAssembly is just a VM standard. It may reference C/C++ as examples as the sorts of languages that could target it but this is primarily because those languages are built on compiler stacks with re-targetable back-ends, not because WebAssembly is specifically aimed at C/C++ (or Rust, which also get's a nod).
It's rather an alternative to JavaScript which, incidentally, some have used as a back-end target on alternative front-end language implementation, e.g. SmartMobile Studio which transpiles Pascal into JavaScript or even the likes of TypeScript et al.
RemObjects recently added WebAssembly as a back-end to their compiler stack, which means you can target WebAssembly using C#, ObjectPascal, Swift or Java, since these are the front-ends already available on that stack.