Use default params when --destructure-named-params + fix renaming of reserved destructured params

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
new file mode 100644
index 0000000000000000000000000000000000000000..7049614851187f60565dafd556bd85c58a9d5676
--- /dev/null
+++ b/test/codegen/expect/destructuring.js
@@ -0,0 +1,39 @@
+dart_library.library('destructuring', null, /* Imports */[
+  'dart/_runtime',
+  'dart/core'
+], /* Lazy imports */[
+], function(exports, dart, core) {
+  'use strict';
+  let dartx = dart.dartx;
+  function f(a, b, c = 1) {
+    f(a, b, c);
+  }
+  dart.fn(f, dart.dynamic, [core.int, dart.dynamic], [dart.dynamic]);
+  function g(a, b, {c = 1} = {}) {
+    f(a, b, c);
+  }
+  dart.fn(g, dart.dynamic, [core.int, dart.dynamic], {c: dart.dynamic});
+  function invalid_names1(let$, func, arguments$) {
+    f(let$, func, arguments$);
+  }
+  dart.fn(invalid_names1, dart.dynamic, [core.int, dart.dynamic, dart.dynamic]);
+  function invalid_names2(let$ = null, func = 1, arguments$ = null) {
+    f(let$, func, arguments$);
+  }
+  dart.fn(invalid_names2, dart.dynamic, [], [core.int, dart.dynamic, dart.dynamic]);
+  function invalid_names3({["let"]: let$ = null, ["function"]: func = null, ["arguments"]: arguments$ = 2} = {}) {
+    f(let$, func, arguments$);
+  }
+  dart.fn(invalid_names3, dart.dynamic, [], {let: core.int, function: dart.dynamic, arguments: dart.dynamic});
+  function names_clashing_with_object_props({constructor = null, valueOf = null, hasOwnProperty = 2} = Object.create(null)) {
+    f(constructor, valueOf, hasOwnProperty);
+  }
+  dart.fn(names_clashing_with_object_props, dart.dynamic, [], {constructor: core.int, valueOf: dart.dynamic, hasOwnProperty: dart.dynamic});
+  // Exports:
+  exports.f = f;
+  exports.g = g;
+  exports.invalid_names1 = invalid_names1;
+  exports.invalid_names2 = invalid_names2;
+  exports.invalid_names3 = invalid_names3;
+  exports.names_clashing_with_object_props = names_clashing_with_object_props;
+});