simplify generation of functions

test/codegen/expect/destructuring.js

Index: test/codegen/expect/destructuring.js
diff --git a/test/codegen/expect/destructuring.js b/test/codegen/expect/destructuring.js
index 4558340a586584684e239820ed4894e36a5c1c30..efdcebabb81f9b7a4ee7e7824c14d4656a9405f1 100644
--- a/test/codegen/expect/destructuring.js
+++ b/test/codegen/expect/destructuring.js
@@ -9,12 +9,12 @@ dart_library.library('destructuring', null, /* Imports */[
     f(a, b, c);
   }
   dart.fn(f, dart.dynamic, [core.int, dart.dynamic], [dart.dynamic]);
-  function f_sync(a, b, c = 1) {
+  function f_sync(a, b, c) {
     return dart.syncStar(function*(a, b, c = 1) {
     }, dart.dynamic, a, b, c);
   }
   dart.fn(f_sync, dart.dynamic, [core.int, dart.dynamic], [dart.dynamic]);
-  function f_async(a, b, c = 1) {
+  function f_async(a, b, c) {
     return dart.asyncStar(function*(stream, a, b, c = 1) {
     }, dart.dynamic, a, b, c);
   }
@@ -23,12 +23,12 @@ dart_library.library('destructuring', null, /* Imports */[
     f(a, b, c);
   }
   dart.fn(g, dart.dynamic, [core.int, dart.dynamic], {c: dart.dynamic});
-  function g_sync(a, b, {c = 1} = {}) {
+  function g_sync(a, b, opts) {
     return dart.syncStar(function*(a, b, {c = 1} = {}) {
     }, dart.dynamic, a, b, opts);
   }
   dart.fn(g_sync, dart.dynamic, [core.int, dart.dynamic], {c: dart.dynamic});
-  function g_async(a, b, {c = 1} = {}) {
+  function g_async(a, b, opts) {
     return dart.asyncStar(function*(stream, a, b, {c = 1} = {}) {
     }, dart.dynamic, a, b, opts);
   }