Let parsing recover from no expression after a ;

[MeAmAnUsername]

Summary
Let parsing recover from no expression after a ;

Todo

• Figure out how to do this
• Implement

Example

func example() -> int = {
  hello;
  // missing expression
}

Reason
Right now, Spoofax just stops parsing if there is no expression between semi-colons. It would be nice if it could recover and show an error like "Missing expression"

Implementation
Add a recover attribute to <Exp>; so that ending an expression with a semicolon and not starting the next expression yet can still be parsed.
Question is where exactly the {recover} should be added.

Additional info
See https://www.spoofax.dev/references/syntax/recovery/

Search terms
Recovery, parsing, grammar, semi-colon, block, body

Related issues
Other issue for making grammar more permissive: #85, #215, #280