Mentioned in other comment, but this is what I did at https://github.com/cretz/vitaslop for Vita. Generic ARM-to-WASM transpiler.

yes, and its probably where this should go. The recompiler itself is plain C++ and builds for wasm easily, the heavy part is compiling its output (GoW2 becomes about 670k lines of Cpp), which would need clang running in the browser. The nicer route is to have the recompiler emit WebAssembly directly and let the browsers own engine compile it. I already do that for VU1 microprograms that were not seen AOT. It also solves distribution you'd pick your own ISO and the conversion would happen locally, so nothing derived from the game is ever hosted.