Compile decorators properly when googmodule is false and transformTypesToClosure is true

[claydiffrient]

This adds a few example decorators to test if they are doing what we need them to do.

Modifies the handling of decorators to make sure they don't do anything that closure gets mad about.

The instructions here should still work for testing: #1

[claydiffrient]

This is the error I keep getting:

❯ npx google-closure-compiler \
--js='*.js' \
--js_output_file=out.js \
--source_map_include_content \
--generate_exports \
--export_local_property_definitions \
--language_in=UNSTABLE \
--module_resolution=NODE
./using_decorators.js:1:18: WARNING - [ES6_MODULE_REFERENCES_THIS] The body of an ES6 module cannot reference this.
  1| var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
                       ^^^^

./using_decorators.js:1:26: WARNING - [ES6_MODULE_REFERENCES_THIS] The body of an ES6 module cannot reference this.
  1| var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
                               ^^^^

./using_decorators.js:21:13: ERROR - [JSC_CANNOT_CONVERT_YET] Transpilation of 'Classes with possible name shadowing' is not yet implemented.
  21| let Person = class Person {
                   ^^^^^^^^^^^^^^
  22|     name_;
      ^^^^^^^^^^
...
  43|     }
      ^^^^^
  44| };

[ribrdb]

Do you have the ts option to import tslib? Tsickle has its own version of tslib.