[Js_of_ocaml] Update jsoo build process for libbinaryen (#8565)

When #7995 was merged it broke our upgrade process in libbinaryen.

This pr fixes our build process.

JS_OF_OCAML still doesn't support esm modules however it supports es6
features, so we can safely remove `target_link_libraries(binaryen_js
PRIVATE optimized "--closure-args=\"--language_out=ECMASCRIPT5\"")`.

Because we are not using esm modules and jsoo doesn't support top level
awaits we need to dissable async compilation.

Author: spotandjake

CMakeLists.txt

@@ -550,8 +550,8 @@ if(EMSCRIPTEN)
   if(JS_OF_OCAML)
     # js_of_ocaml needs a specified variable with special comment to provide the library to consumer
     target_link_libraries(binaryen_js PRIVATE "--extern-pre-js=${CMAKE_CURRENT_SOURCE_DIR}/src/js/binaryen.jsoo-extern-pre.js")
-    # Currently, js_of_ocaml can only process ES5 code
-    target_link_libraries(binaryen_js PRIVATE optimized "--closure-args=\"--language_out=ECMASCRIPT5\"")
+    # js_of_ocaml does not support top level await
+    target_link_libraries(binaryen_js PRIVATE "-sWASM_ASYNC_COMPILATION=0")
   else()
     target_link_libraries(binaryen_js PRIVATE "-sEXPORT_ES6")
   endif()