QWasmSuspendResumeControl manages transfer of control from JS to the wasm instance, when the wasm instance is asyncify suspended. Supported use cases include registerEventHandler()-type event handlers, and also JS APIs which take a callback functions, such as timers and requrestAnimationFrame. The specific use cases are handled by adapters (not included in this commit), which call the QWasmSuspendResumeControl API to register JS/C++ event handler pairs: uint32_t index = control->registerEventHandler([](val){ ... }); val jsHandler = control->jsEventHandler(index); The C++ handler contains the user code, while the JS handler can be passed to registerEventHandler or be used as a callback. Change-Id: Ia1b1fd8884f0906759690dc7bc949c65a0248618 Reviewed-by: Jøger Hansegård <joger.hansegard@qt.io>