Handle dynamic as bottom inside of function type reps

test/codegen/expect/sunflower/sunflower.js

 dart_library.library('sunflower', null, /* Imports */[
   "dart_runtime/dart",
   'dom',
   'dart/core',
   'dart/math',
   'painter',
   'circle'
 ], /* Lazy imports */[
 ], function(exports, dart, dom, core, math, painter, circle) {
   'use strict';
@@ skipping 19 matching lines @@
       return dart.as(querySelector("#slider"), dom.InputElement);
     },
     get notes() {
       return querySelector("#notes");
     },
     get PHI() {
       return (dart.notNull(math.sqrt(5)) + 1) / 2;
     }
   });
   function main() {
-    exports.slider.addEventListener('change', dart.fn(e => draw(), dart.void, [core.Object]));
+    exports.slider.addEventListener('change', dart.fn(e => draw(), dart.void, [dart.dynamic]));
     draw();
   }
   dart.fn(main, dart.void, []);
   function draw() {
     exports.seeds = core.int.parse(exports.slider.value);
     exports.context.clearRect(0, 0, MAX_D, MAX_D);
     for (let i = 0; dart.notNull(i) < dart.notNull(exports.seeds); i = dart.notNull(i) + 1) {
       let theta = dart.notNull(i) * dart.notNull(painter.TAU) / dart.notNull(exports.PHI);
       let r = dart.notNull(math.sqrt(i)) * dart.notNull(SCALE_FACTOR);
       let x = dart.notNull(centerX) + dart.notNull(r) * dart.notNull(math.cos(theta));
@@ skipping 19 matching lines @@
   exports.SEED_RADIUS = SEED_RADIUS;
   exports.SCALE_FACTOR = SCALE_FACTOR;
   exports.MAX_D = MAX_D;
   exports.centerX = centerX;
   exports.centerY = centerY;
   exports.querySelector = querySelector;
   exports.main = main;
   exports.draw = draw;
   exports.SunflowerSeed = SunflowerSeed;
 });