message: Document and rename collect_loads
  Summary: Calling it `loads()` seems fine. Add documentation.
diff: @@ -114,7 +114,11 @@ impl AstModule {
  Ok(AstModule { codemap, statement })
  }
  - pub fn collect_loads(&self) -> Vec<&str> {
  + /// Return the file names of all the `load` statements in the module.
  + /// If the `Dialect` had `enable_loads` set to `false`, this will be an empty list.
  + pub fn loads(&self) -> Vec<&str> {
  + // We know that `load` statements must be at the top-level, so no need to descend inside `if`, `for`, `def` etc.
  + // There is a suggestion that `load` statements should be at the top of a file, but we tolerate that not being true.
  fn f<'a>(ast: &'a AstStmt, vec: &mut Vec<&'a str>) {
  match &ast.node {
  Stmt::Load(module, ..) => vec.push(&module.node),
  @@ -132,6 +136,7 @@ impl AstModule {
  loads
  }
  + /// Look up a span contained in this module.
  pub fn look_up_span(&self, x: Span) -> SpanLoc {
  self.codemap.look_up_span(x)
  }
  