7149b90c7c
Side effect of this: Fix bug where helpers in js_mirrors were specifying that name had to have type String when it could really also be a JS Symbol as well. Fix bug where top level JS interop members using the external keyword but no @JS keyword were not implemented. Update js_typed_interop_test.dart so it can work in DDC. Add regression test for jsify call with native function type arguments. BUG= R=vsm@google.com Review-Url: https://codereview.chromium.org/2827333003 .