message: [core] Add experimental format export to memory
diff: @@ -25,6 +25,7 @@ mod no_std_defs {
  boxed,
  string,
  vec,
  + format,
  };
  /// Collection types.
  @@ -48,6 +49,7 @@ mod std_defs {
  boxed,
  string,
  vec,
  + format,
  };
  /// Collection types.
  