Support Asyncify + Try-Catch [Can't build web-gphoto2 with -fwasm-exceptions instead of -fexceptions]

web-gphoto2 builds with pthreads, Asyncify, exceptions and LTO, and I'm not sure which combo is specifically problematic here, but the end result is that it crashes when trying to switch from -fexceptions to -fwasm-exceptions:

unexpected expression type
UNREACHABLE executed at /b/s/w/ir/cache/builder/emscripten-releases/binaryen/src/passes/Asyncify.cpp:998!
emcc: error: '/emsdk/upstream/bin/wasm-opt --strip-dwarf --post-emscripten -Os --low-memory-unused --asyncify --pass-arg=asyncify-imports@env.invoke_*,env.__call_main,env.emscripten_sleep,env.emscripten_wget,env.emscripten_wget_data,env.emscripten_idb_load,env.emscripten_idb_store,env.emscripten_idb_delete,env.emscripten_idb_exists,env.emscripten_idb_load_blob,env.emscripten_idb_store_blob,env.SDL_Delay,env.emscripten_scan_registers,env.emscripten_lazy_load_code,env.emscripten_fiber_swap,wasi_snapshot_preview1.fd_sync,env.__wasi_fd_sync,env._emval_await,env._dlopen_js,env.__asyncjs__* --zero-filled-memory --strip-debug --strip-producers ui/libapi.wasm -o ui/libapi.wasm --mvp-features --enable-threads --enable-mutable-globals --enable-bulk-memory --enable-sign-ext --enable-exception-handling' failed (received SIGABRT (-6))

A branch that's failing can be checked out from here: https://github.com/GoogleChromeLabs/web-gphoto2/tree/fwasm-exceptions. It should be pretty reproducible as it uses Docker, so all you need to do is run ./build.sh in the checkout folder.

Check out the fwasm-exceptions branch in web-gphoto2 and run ./build.sh to reproduce the wasm-opt crash. Start with Asyncify.cpp around line 998 and the reported wasm-opt invocation; done means the build completes with Asyncify, try-catch, threads, exceptions, and LTO enabled.