add regenerator parameter tests

test/fixtures/transformation/regenerator/default-parameters/exec.js

@@ -0,0 +1,6 @@
+function* foo(foo = "bar") {
+  return foo;
+}
+
+assert.deepEqual(foo().next().value, "bar");
+assert.deepEqual(foo("foo").next().value, "foo");

test/fixtures/transformation/regenerator/destructuring/exec.js

@@ -0,0 +1,5 @@
+function* foo({ foo }) {
+  return foo;
+}
+
+assert(foo({ foo: "bar" }).next().value, "bar");

test/fixtures/transformation/regenerator/rest-parameters/exec.js

@@ -0,0 +1,5 @@
+function* foo(...items) {
+  return items;
+}
+
+assert.deepEqual(foo(1, 2, 3).next().value, [1, 2, 3]);