Added minimal test case for markdown comment parsing with JLS 23

[trancexpress]

See: #2679

What it does

How to test

Author checklist

• I have thoroughly tested my changes
• The change is following the coding conventions
• I have signed the Eclipse Contributor Agreement (ECA)

[trancexpress]

New test produces:

org.eclipse.jdt.core.compiler.InvalidInputException: Unterminated_Comment
	at org.eclipse.jdt.internal.compiler.parser.Scanner.unterminatedComment(Scanner.java:5514)
	at org.eclipse.jdt.internal.compiler.parser.Scanner.getNextToken0(Scanner.java:1799)
	at org.eclipse.jdt.internal.compiler.parser.Scanner.getNextToken(Scanner.java:1227)
	at org.eclipse.jdt.internal.core.util.PublicScanner.getNextToken(PublicScanner.java:117)
	at org.eclipse.jdt.ui.tests.core.source.GenerateGettersSettersTest23.testMarkdownComment(GenerateGettersSettersTest23.java:881)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)

Test works with JLS 21, but not with JLS 23.

@iloveeclipse this might be a compiler change/bug?

[iloveeclipse]

I assume there is a (yet another) bug in markdown comments support.
See https://github.com/eclipse-jdt/eclipse.jdt.core/issues?q=is%3Aissue%20state%3Aopen%20markdown

See https://openjdk.org/jeps/467, Java 23 is where the feature is supposed to be introduced.