common: fix build on aarch64 and others

On aarch64 for example, function alignment is 4 so we need to
@alignCast() when casting ?*const anyopaque to function pointers.

src/common_core.zig

@@ -100,7 +100,8 @@ pub fn Dispatcher(comptime Obj: type, comptime Data: type) type {
                         }
                     }
 
-                    @ptrCast(*const fn (*Obj, Payload, Data) void, implementation)(
+                    const HandlerFn = fn (*Obj, Payload, Data) void;
+                    @ptrCast(*const HandlerFn, @alignCast(@alignOf(HandlerFn), implementation))(
                         @ptrCast(*Obj, object),
                         @unionInit(Payload, payload_field.name, payload_data),
                         @intToPtr(Data, @ptrToInt(object.getUserData())),