LibJS: Link AsyncBlockStart AO to Explicit Resource Management proposal

As this function already implements that proposal.

Userland/Libraries/LibJS/Runtime/ECMAScriptFunctionObject.cpp

@@ -772,6 +772,7 @@ void async_function_start(VM& vm, PromiseCapability const& promise_capability, T
 }
 
 // 27.7.5.2 AsyncBlockStart ( promiseCapability, asyncBody, asyncContext ), https://tc39.es/ecma262/#sec-asyncblockstart
+// 12.7.1.1 AsyncBlockStart ( promiseCapability, asyncBody, asyncContext ), https://tc39.es/proposal-explicit-resource-management/#sec-asyncblockstart
 template<typename T>
 void async_block_start(VM& vm, T const& async_body, PromiseCapability const& promise_capability, ExecutionContext& async_context)
 {