Avoid syntax errors.

[HansOlsson]

Avoid the use of {} that isn't described in the grammar.

[henrikt-ma]

I find the old way with {} much more clear, and it has never been a concern to me that annotations are defined using a style which only reminds of – but isn't exactly – Modelica.

We already have the big discrepancy that there is no built-in record called Documentation, and that's not a problem.

I see two better-looking alternatives to fill("foo", 0):

• General use of {} rather than fill("foo", 0) when defining annotations with defaults.
• General rule that array annotations always default to being empty. (Corresponding to suggestion in Define more annotations as declarations #3448 (comment).)

[henrikt-ma]

Nothing really changed since my previous review. More discussion is needed to sort this out.