message: Make assert::module return the FrozenModule
  Summary: Useful to allow us to do more with the Assert framework
diff: @@ -301,7 +301,7 @@ impl Assert {
  /// a.module("hello.star", "hello = 'world'");
  /// a.is_true("load('hello.star', 'hello'); hello == 'world'");
  /// ```
  - pub fn module(&mut self, name: &str, program: &str) {
  + pub fn module(&mut self, name: &str, program: &str) -> FrozenModule {
  let module = self
  .with_gc(|gc| {
  let module = Module::new();
  @@ -309,7 +309,8 @@ impl Assert {
  module.freeze()
  })
  .expect("error freezing module");
  - self.module_add(name, module);
  + self.module_add(name, module.dupe());
  + module
  }
  /// Set the [`Globals`] that future tests have access to.
  